First things first. This is your first HAUL OUT. A "pull out" is a completely different kettle of fish. Not sure when it was pulled or painted last... I assume this means there is bottom paint on the boat now. Do you know what kind? Do you know if the boat already had a barrier coat done by the previous owner? If you can't answer "yes" to both of the above questions, can you contact the PO and ask? I would recommend at least trying to get those answers before going further into this.
Pressure washing should take care of most of the growth. Check on costs of having the boat yard do it if the EPA issue is a problem in your area. (I'm guessing it is.)
hunter Legend 37 Semper Paratus
Formerly - Tartan 34C Yawl