Foundation wall for covered porch turned sunroom
Why not call it a three season room only? Just kidding
Block it up as high as you can, keep it about 2" down from the existing framing, use semi solids for the top course, install anchor bolts.
Line up a 2x6 P.T. piece of wood and mark the anchor bolts, drill out for the anchor bolts then cut the 2x6 'U' shape to slide it in to the bolts, use shims to hold to up tight to the floor system/existing framing, use high strength grout to fill the gap between top CMU block and bottom of new sill plate, usually have to pack the grout from both sides to get it all the way in and make it effective.
once dry, grout dries quick, remove the shims and grout that gap, install square 2 1/2" washers and nuts on anchor bolts, secure the floor system to the top plate, suggest a A-35 clip from Simpson every 16" or whatever your code requires.
Insulate walls, preferably spray foam, also, if you have heat ducts running see if you can have one added to blow into the area below the floor, hot air rises and it keeps the chill off the floor.
Use dryvit or sto to cover the outside of the blocks, trowel it on, basecoat first than finish coat, essentially it is stucco, just acrylic based