Rapid Tournament Friday April 22nd Questions

For the rapid tournament this friday, how many people typically participate, how do the ratings/rounds/pairings work, and are there any processes/registration fees required to participate? Sorry for the possibly seemingly obvious questions, I'm new here and to the scene of official chess tournaments/federations in general. 

around 40 ppl join but more join during it

ratings count for uscf ratings even tho it chess.com rated

for pairings you can look up the swiss system pairings

and as long as ure us chess member ship is fine u fine

There's a whole schedule somewhere for tournaments 

https://www.chess.com/clubs/forum/view/tournament-schedule 

blunder