A sheet attached to the loop will travel a set distance.
Often the mizzen and staysail (or jib) need similar sheet travel, and the main sheet needs about twice this travel.
Using a pulley you can half or double the sheet travel distance.
So one sheet can control the mizzen and jib, and a second sheet via a pulley serves the mainsail. (Or you can have separate sheets for the mizzen and jib, attached to the loop at the same point, but each leaving the hull via its own exit eye.)
The use of two or more winches is rarely needed but make sure that your winch has sufficient 'strength' to handle your sails. A single winch is easiest to install and easiest to sail; also lighter.
Each sheet should ideally be adjustable by passing it through a bowsie on the boom. Differences in sail 'set' can then be accommodated.
I'm not sure that the lengths of your cords helps unfathom all this. (Excuse the nautical term !) Anyhow, I hope the above is of some help.
Your build is coming along beautifully, but make sure all th😉e sail controls are sorted out before you put the deck on !
Good luck 😉