I'd raise the main at the slip since you're heading upwind anyway..one less thing to do later. Don't cleat it down, just let it float until you're ready to motor forward, then trim to keep the boat flat and/or keep the sail from flapping. Wait till you get close to the sailing area before hoisting the jib, besides minimizing the sail's flapping it will be easier to handle the boat under power and insure good visibility in a crowded anchorage.
If you're sailing out of the slip, you should hoist both sails before leaving, but don't lock down the sheets... leave the main uncleated, letting it weather vane, and backwind the jib to start the boat backwards and push the bow in the direction you want... as the boat drifts into position, release the backwinded jib , trim in the main to get going forward and resheet the headsail normally as you beam reach down the fairway. I wouldn't cleat anything down until you clear the other boats so you can luff the sails immediately for speed or direction adjustments.
To get a better feel for how your sails interact with each other and the boat... lock the rudder amidships and try to steer the boat with sails only. More pressure on the jib... the boat will want to bear off (lee helm). More pressure on the main, the boat will try to head up (weather helm). Balanced rig... the boat sails straight and true (hopefully). You can also experiment with crew weight placement (ballast) in this exercise.