There is a story about the UK census in 1921 (it may not be true, but it should be). The form had a space for "Occupation", and a space for further details if your job was unusual. One form read:
Occupation: Carver of stone lions
What does this involve? I carve away all the stone that isn't lions
This is much more helpful for uke-making than you might think.
Step one is to do reading, lots of it. Everything you need to know is available online, but it's scattered about. Go looking.
If you want an easy start, buy a sheet of 1/16 inch plywood, a piece of straight-grained 2 x 2 hardwood about 24 inches long, and some 1/4 square strip. Make the body out of the plywood, kerfing the strip to make linings and using offcuts from the 2 x 2 for the neck and tail blocks. Make the neck bolt-on using an insert into the heel. Make a one-piece bridge out of 2 x 2 offcuts. Set the frets direct into the neck, and paint the body before bolting on the neck.
Look up the terms you don't know, because you need to understand what those parts do and how they function. You will need fret wire, tuning machines of some kind, a saw, a drill, a rasp (half-round), and sandpaper. Chisels and planes make things easier. Clamps for glueing bits together.
If this uke plays a tune, you now know enough to try again using real wood (planes and scrapers will be needed here). Just remove all the wood which isn't a uke. After the first half dozen you will begin to get a feel for what you are doing.