If you want to play OTB tournaments then do it. They are the best and funnest way to play chess. There is no "level" you need to be at. I have thrown students that know how the pieces move into tournaments and they enjoyed it. The longer you wait to be ready, the more time you wasted.
What are some basic concepts that I need to study to get to 1000 rapid? such as pawn structure, middle game, end game.