There are two lakes near the center of the map. I would drain the southern lake into a large 11x11 farming area under and just to the left of it. It would overflow the space, but the 11x11 space can be neatly divided into four 5x5 plots with a seed barrel in the middle, which is all that a fort really needs. So a floodgate would be useful to control flooding.
The second lake would become a fishing lake, and I'de build a wall around it with some extra room for a fishery, storage for empty barrels and barrels of fish, and a little fisherman's hut. If the fishing's good, might build a fish-cleaner's hut and a second fisherman's hut.
Also inside the walls a path into the fort proper, and maybe space for outdoor crops and a refuse pile. If outdoor farming is gonna be a thing, then space for several farmer's huts, farmer's workshop, still, butcher's shop and a mill. Future expansion could include an outdoor garden where animals can congregate, near the farmer's workshops for easy milking and slaughter.
The main gate would face the river, and have a little bridge crossing it. And on top of the walls on the inside there would be a catwalk for archers should the need arise.