There is a $6 charge to enter the marina grounds with (or without) a boat. After entering, turn left at the T intersection (the stop sign) to go to the South Ramp area where most AYC Members launch their boats. On race weekends, you’ll see a flock of AYCers setting up at Spinnaker Point (just to your left as you sit at the T after entering the grounds). If you turn right at the T, you’ll usually see the Thistles and others on the paved north lot, preparing to launch at the North Ramp.
You can also launch from the county park boat ramps or Scorpion Bay Marina, but most AYC off-the-water activities happen at Spinnaker Point, on marina land, at the south end of the lake. Here’s information on the county park and the Lake Pleasant area from Maricopa Parks and Recreation.