Don’t expect to much from a gym date, take it for what it is and maybe develop into a healthy drink or food afterwards.
Don’t use corny gym phrases, ask lots of questions if he’s instructing you. Most men like to do the asking as it takes the pressure of off them, this makes a good opportunity for it to be the other way around.
you don't have to worry about a thing, there is nothing that a girl can do to turn off a guy.
depends how you want to play it don't pretend like you don't need him or you may make him feel like a smaller man but don't be completley helpless either as you could be seen as clingy and not independant