,what Micro bloc
A microblock is just a small pulley -- looks like this:
Its job is to eliminate friction in the "main sheet" and make the sail more responsive to quick and easy handling. On the PA it attaches to the padeye just aft of the cargo well. One end connects to the sail and the the other is held in your hand. It can be cleated off in light winds.
If you're new to sailing, there are a few things to learn before using it while fishing. The last thing you want is to capsize in a sudden wind gust with your fishing gear not tethered -- it might tend to leave you with a bad impression.
1. Read up on basic sailing and sail handling what makes the sail pull the boat upwind, what wind directions you can sail how to present the sail to the wind, turning (tacks, jibes, etc), how the centerboard works (your fins act as your centerboard) and so forth.
2. Rig your boat with the block. I find it much simpler to permanently separate the mainsheet from the sail for quick sail set-up and take down -- just connect it with a snap hook:
Make a separate small "tail" to secure the sail:
3. Practice sailing (including raising and lowering sail) without any fishing gear until you get comfortable with the procedure with some decent wind and get used to the heel. Learn how to luff when necessary and how to tack as a substitute for jibing when the wind is gusty.
4. You'll be a pro in no time. Have a blast!