I will be a sopre next year and i was wondering if i should take the PSATs now or wait till junior year?

I suggest that you take it both sopre and junior year. In your sopre year, taking the PSAT's will not count against you. It will show you what level you're on and may give you a direction to study for the SAT's. Then, if you do study, you can take the PSAT's in junior year, and if you do well, you'll qualify for as a merit scholar, but I'm not too sure what that is. So, in my opinion, take it now, and then junior year again.