I am trying to get a better grasp of what certain spices taste like. Tasting them straight is a little overpowering. What do you suggest as a "medium" to add spice to to learn what the flavor is?

Chicken is a really good medium to try spices (or something like tofu if you are vegetarian)

Everyone kind of has a good idea of what chicken (or tofu) tastes like on its own and then you have two options:

1) Dry rub with different spice blends
2) Make different sauces with different spice blends

Another option would be create some little dishes of olive oil + baguette. The baguette plus olive oil on its own is your baseline and then add in the different spices and you should taste the differences

If you have a Penzey's spices near you it would be worth a visit. They have every spice and herb imaginable and have an open jar of each one so that you can smell them (at least they did before Covid). I find that spices often taste like what their aroma is.
If not, places like Cost Plus World Market and some grocers (Sprouts) often sell various spices in little plastic bags and they are way cheaper....some spices are pricey and if you just want to try but aren't sure this is a good way to do it.
Also, some spices are fat soluble meaning the flavor doesn't really bloom unless it is mixed with a fat during cooking or preparing.

Rice is a good neutral background for many spices.

But "spices" is a really broad term. There are some that go best on meat, others add flavors to cakes. What is your cooking end goal?

Really just to learn what they are. I accept that my sense of taste does not always conform to everyone else's, so if I am going to use them, I need to know what they taste like to me. I will probably go the oil and bread route, since that is simple and will let me do a few at a time.

Oil, especially olive oil, can really change how some flavors are perceived. The oil can be so cloying that you don't actually taste the seasoning unless it is extreme.

Other things to consider are how fresh the spice is, is it finely ground or coarse texture, whole leaf, etc. For example, oregano fresh from my garden has a much "sharper" taste than the leaves I dry to use over the winter. Have you considered getting a book on spices, which might suggest the optimal ways to taste them?

What sort of foods do you like (especially of non-US ethnic varieties)? This can give us an idea of flavo(u)r / spice profiles that you already probably know, but don't know you know it, like cumin, coriander, turmeric, various "warm" spices, various ground peppers such as paprika, aleppo, and so on.

I think a neutral tasting oil is preferable to olive oil here...like grapeseed oil. This seems like quite a project ...having to buy a bunch of spices and tasting each one.

I'm not going to go through every spice, just a few of them.

I already know cumin, cloves, cinnamon, pepper, chili/chili powder. What I am a little vague on, and really want to get a better idea of, are cardamom, nutmeg, coriander seed, fenugreek ( I think that is considered a spice), nigella, and turmeric, even though I am sure i do not like the last. Fortuntely there is a shop in Worcester that sells small amounts of herbs and spices, so I don't need to go to the Indian market and spend a fortune on stuff I will end up not using.

For cardamom and nutmeg, bread and oil would not work well. They're usually used in baking - cakes, sweet breads, cookies, or sweet beverages - spiced cider, chai, spiced hot chocolate.

I'd suggest sprinkling them on something sweet-ish, like rice pudding, vanilla pudding, yogurt, applesauce, etc. Pre-ground or grated cardamom loses flavor within a couple weeks, so try to get it as fresh as possible if you don't want to grind it yourself.

The thing is that you may not care for one spice or another on its own, or in the wrong quantity on the wrong thing. For example, I made some chicken today with Ras el Hanout. Any of the spices (there are 17 or so) in this blend, save a few, don't really work on their own. Add too much cardamom, or clove, or allspice to your dish and it could end up inedible. Take, for instance, zhoug - a Yemeni hot sauce, with cumin, cardamom and cloves (not to mention lots of parsley, cilantro, garlic and green chiles) - but when eating it, it just tastes of delicious and you couldn't really identify the cardamom and cloves specifically, which is a good thing. But you'd know something is missing if it were missing.

And once you find things you really like, you'll buy certain specialty items from the spice shop, and others in larger quantities from the ethnic markets (those that have a good volume turnover of the spices) or Costco, etc.

Don't hesitate to ask a good spice shop regarding recommended blends for certain flavo(u)r profiles. For further example, my favo(u)rite local spice shop has a Urumqui rub, most recommended for lamb, but I made a delicious pig loin with it a few days ago.

I agree spices can get very complex, and indeed my intrest in getting to know more about them is an interest in getting to know Indian food better. But you need to start with a foundation, and that is understanding what each spice tastes individually. I use several masalas, but I am confused understanding the differences between both blends and companies because I don't understand the individual spices.

I love this thread and can relate utterly with the desire to understand the parts that make up the sum.

Have spent years doing just this with Japanese food and then branching out to take in South Korean and Chinese spices and ingredients.
India is another world.

As [MENTION=64453]CDTraveler[/MENTION] explained, fats and oils will change your perception of spices. For some, they will unlock flavours (and heat can play its own part in this), but for others, it can tame or even mute them.

For actually “tasting” wasabi rather than just succumbing to the eye watering pungency, it’s recommended to spread it on pure white chocolate which is mostly made up of cocoa fat. So long as you can get a decent quality bar without too much sugar and vanilla, this should make a useful neutral base to see how fat changes an ingredient. Ice cream can be another very enjoyable way of getting to know a spice. Cheese and yogurt are prevalent in Indian cooking and white chocolate/ice cream can help with understanding their effects too.

Lightly frying an ingredient in canola/rapeseed or another oil or ghee, then allowing the oil to cool and tasting the result (with bread, mixed with pasta, on vegetables etc…) with and without salt, will show you another flavour profile

For understanding how flavours change when dissolved (again, with or without heat) an ideal base which is rich in amino acids (these also affect perception) is kombu dashi. It’s a simple broth made with water and kombu/konbu kelp. It’s essentially flavourless apart from having umami.
A bland chicken stock will provide a similar base.

I didn't think of the cocoa Butter thing. I actually have a bag of the stuff.

Nutmeg in mashed potato. Both tastes nice and gives an idea of the flavour.

Tumeric is not strongly flavoured, but using a lot in rice to make very yellow rice (add peas and fried onion) will reveal the flavour. Then, in a later batch add whole cardamon seeds, but don't eat the seeds themselves.

By coriander seed do you mean ground coriander, not whole seeds. If you know cumin already, try a mixture of 2 parts ground coriander and 1 part cumin in the same dishes you would use cumin.

Fenugreek - try experimenting with a very simple 'curry' spice mix made from fenugreek, cumin, coriander, tumeric, and chili powder. Start with 2:1 coriander and cumin and add other spices. Cook using frozen ginger garlic mix as well. And, consider adding tomato puree and creamed coconut. For amounts, start small and add more later.

EDIT: Try amchoor powder? It's dried and ground green mangoes. It adds a fruity sour flavour to food.