The size of the 1K corral varies widely from airport to airport. In SFO, there might be as many GSes as you get 1Ks in BOS (which is to say, "a lot"). But in CLT, IND, or LAS you might one of two, maybe three 1Ks, as happened to me this year in each of those airports. The best attitude is one where you expect nothing more than the value you pay for your ticket (you paid for coach? expect to sit in coach), so that you can be pleasantly surprised by anything that comes from being 1K.

As others have said above there are lots of small things that we as 1Ks start to take for granted. Boarding early means you will essentially always have your rollaboard in the overhead compartment, by your seat. Getting a free meal and alcoholic drink when flying in back. Free, extra luggage allowance.

But the best parts kick in either for international travel, where the conferred Star Gold status gives you access to lounges (use them!), even for initial domestic-US legs; or durring IRROPS, where 1Ks are proactively taken care of and get a higher level of service, like free lodging, even for weather delays.

It is worth boning up on the lingo so that you can communicate in a more native tongue with UA staff, learning terms like PNR, TATL, TPAC, IRROPS, GG OVS DOWNGRADE, etc. Flyertalk is your best source of information on that front. I've learned a ton here, for which I am very grateful!