You shouldn’t be playing then honestly.
If you don’t have 3 buy-ins with you, you shouldn’t sit at the game as you won’t be playing correctly always worrying if you lose a hand that you can’t play anymore.
But if you are going to play, and with only one buy-in here is my general advice:
Play tight, play in position as much as possible, come in raising, and raise big. Don’t open for $7 or even $10. If you are playing strong hands you want 1 maybe 2 callers not a table full. I make my standard open $15, except for maybe if I’m in the bottom and it has folded to me I would say $10. But that is rare.
Don’t bother trying to bluff, it isn’t worth it at these stakes the vast majority of the time. Bet your made hands. Don’t expect others to do it for you! Build a pot early when you are strong, don’t wait until the river to try making money. The draws have already missed and will fold or are now beating you.
If you raise with AK and get 4 callers just check fold if you miss the flop. No point in trying to C-bet, you will get called and just waste money.
If start winning and you think the other players are catching on to you, don’t worry about it, more fish will be coming in, don’t change how you are playing.