How old is your boat? do you have the "old style" mast base (no hole in the little nub that extends down) or the new style (hole in the nub).
The new style is much easier to deal with (and safer), since the mast is attached to the step with a hinge link. It's easy to retrofit. In either case, you lay the mast along the trampoline, hook up the side-stays, then lift the mast up and attach the forestay. There are ways to do this by yourself - you can search this site for them.
Trailer to Water
Most Hobie sailors avoid launching ramps if there's a way to get to a beach without dealing with a ramp. Beach wheels (Cat Trax, Euro Trax) are almost a must:
If the beach is soft sand (not a lot of rocks), dragging the boat around will not hurt it significantly.