There's two parts to being handy and 'fixing stuff'.. one is some 'feel' for shapes, measurements and material-- the ability to see 3D in your head. I got a high score one that in 7th grade, but thought I had no interest.

The 2nd is just one-step-at-a-time practice.... and if step 1 exists, the rest will come gradually. Things like changing a lamp switch and/or cord... using s screwdriver or hammer on a small job. I one had to unstick a window to get it raised, and a young lady I knew was watching and wanted detailed info... seem her dad never bothered to show 'girls' that stuff. I used a screwdriver to loosen it a bit, then a piece of wood as a fulcrum to avoid damage. That data about fulcrums and levers was pure Archimedes, and was 1st step in applications to things like changing a tire or moving a tree limb.

Plumbing can start with just changing a washer in a leaky faucet... then MY next step... turning OFF the house supply to allow drilling a hole in a pipe to install a water line to a refrigerator. A trip to the hardware store to point at the options will help. It's amazing how soon someone is saying..,"Is that all there is to it? That wasn't hard."

It's not overnight... just as learning where files are located on a computer and how to download & install useful programs in not overnight... (I have friends who have NEVER installed anything and can't tell you where those icons they click are located.)