Requests, if you know it, play it and if not apologize and offer something that comes as close as you can. The smart accordionist that performs in public not only plays what is asked (when possible), but if they don't know, mark it down and learn it later. If it was requested once, it is a high chance of being requested again.
I was playing in Ottawa and there was this man from the German consulate, he asked me to play some obscure German song, I apologized that I did not know it, and offered something else that I knew. I asked him to mark down the song on a piece of paper napkin, and maybe a week later researched it... found the song and composer, that led to maybe 5 other songs from that era that I learned too.
It wasn't a month later that the man from teh consulate came back and I am sure he was expecting me to still not know *his* song. I strolled over and started with his original song but I then moved to the other 5 related pieces... the man was in tears and clapping non-stop saying how ti reminded him of days gone by and other things. After I was about to leave, he pulled me over and asked me to open my bellows a little, as if he wanted to look in between, so I did. He promptly put in several $20 bills in the top of the bellows and thanked me again. For a 16 year old kid in the 70's, that was a small fortune!
Moral of the story, if you are a public performer, you have to try to play what the public wants (in short, KNOW your public)... else that is called "playing for yourself"

Congrats on making he decision to gig in public, it takes a special kind of courage and attitude that not many people have!