If it helps, here is how I recently go into "watchmaking". My initial goal was to mod a Seiko (dial, hands, and bezel). Lume Shot on YouTube has many good detailed videos on this. However, I was too nervous to start out on one of my own cherished Seiko's, so I bought a very cheap (both price and quality) mechanical watch from Ali Express for $25. Once I practiced taking apart and putting that watch together a few times, I got enough confidence to mod my Seiko. After modding a few watches, I bought a timegrapher and started regulating every watch within reach. That's where I'm at now. I say go as shallow or deep as you want. Good luck!