how Many days in advance do you have to make a reservation for the shows?

Depends on the demand for the performer you are seeing. I got my tickets 4 months in advance for Justin willman. It was sold out. Seating at Caroline's is first come first serve. Even though I got my tickets 4 months in advance I wasn't right at the double doors like an hour or more in advance to sit at the very best seats, plus there are VIP seats that aren't sold to the public. If there are tickets available only days in advance show up early to get halfway decent seats on the day of the show

It depends. Tickets are on sale for shows into August. They may sell out. If they don't, you can get tickets up until the day of