Ryan,
Did you spray "fogging oil" into the cylinders when you stored it? If not, you may have some surface rust on them from moisture.
What about gas? Did you drain it before storage. If not, drain and fill with fresh.
What about your batteries? Did you remove and store properly?
You should grease all steering rods and put graphite spray into all control cables. Move them VERY carefully so you don't break anything. That can be very expensive.
Check all electrical connections, terminals and switches for corrosion. Clean and check continuity. Be sure all lights and electronics work.
Did you store it with the drain plug removed? If not, remove it and drain any water out of the hull.
Use a good cleaner and conditioner on all your seats, cushions etc.. The upholstery can get dry and hard and needs to be softened up before you sit on them and possibly tear it.
Check the expiration date of all your safety equipment, flares, fire extinguisher, first aid kit items.
Check trailer lights, tires for cracks, grease wheel bearings. Also check your tie down straps for tears/rot.
These should give you a good start. Good luck and enjoy.
Greg