A page from the previously referenced assembly manual shows the pin on the mast base on the top picture. Nacra assembly Manual

Your boat probably uses the wire lock system and the wire was originally long enough to reach most of the length of the mast. There would have been a ball crimped on the wire that latched under a fork at the top/front of the mast when the sail was fully hoisted. The wire then got loosely secured near the bottom of the mast and the rope section stowed.

Regarding raising the mast: Once the sidestays are connected and the mast is secured to the ball place the mast on the trailers mast support. If the trailer is placed next to the back beam the support should have the mast many feet in the air already. You could use a 6 or 8 foot ladder to do the same thing. Then the mast lift isn't starting at your feet.