questions about fraternity rush

I'll be rushing next fall as an oos freshman from the south and I've got some questions.

Is it really competitive or do most people get bids?

Do I have to wait till school starts to sign up for rush or do I do it before then?

I haven't really been able to find out much info about fraternity rush. So is there like a week where you go to all the different houses and then you get invited back to the ones that are interested in you?