gogoflyer
Welcome, a bit late to the party, but you have come to the right place.
The fact is that you have a long way to go to get the best of the board. My suggestions include:
Sets some goals for yourself, before you go wild getting started.
Let us know where you live, or at least the nearest airport...that will help others define a best, second best...etc airline to get point on.
Credit cards generally cost money to have, annual fee. So getting a bunch is not normally cost effective, at least not all at the same time. Also the credit agencies may or may not find you attractive for lending on a mortgage as a retiree with 10 new credit cards, newly minted or newly cancelled.
Think about the hotels you would probably stay in. It will take a long time to generate lots of free stays. These stays will need to generally be earned at the same chain. The problem is, the cost of getting free nights at say Hyatt is high. At Best Western or Choice hotels the cost is much lower. Cost of food, parking, etc often tracks with the cost of the rooms too.
So some thought needs to go into that process. Here on the board most (IMHO) people earn their points on their employers bank (or tax deductible as a small business)for years to come up with free flights, nights, cars, etc. When you are paying to get those benefits, the effort takes some different thought. Also some of the huge ongoing point amassing is dependent on bonus given to only the frequentest of frequent fliers...so seek out some discussions of mileage runs.
Continue to read this site. Spend some time in the "search" areas of forum of interest, as so much has come before that will hone your future questions.
Think airline, hotel, car rental, credit card (paying insurance, doctor bills and biger ticket items helps), phone company, investment company, mortage, groceries, Entertainment card, web based booking for everything, and watch for miscellaneous bonus for everything...most of which ends up somewhere on this board. Also don't join anything until you see what, if any, bonuses you can score in doing so.
Will that is what hoped into my head right off, I am sure you will get lots of advice. It seem like it has been awhile since we have discussed someone retiring and yet just starting.
Good luck. And again welcome