I agree with buying tools as you need them and as you acquire skills.
You'll want basic mechanics tools like a set of metric Allen keys, combination wrenches, adjustable wrench and screwdrivers. Cone wrenches in 13 and 15 mm will be needed soon. Pedal wrench also, though I have a very narrow adjustable that works fine most of the time.
DItto the comment about part-specific tools, especially for the bottom bracket. There are too many "standards."
If it's an option where you live, consider volunteering at a bike coop or non-profit shop. You can get hands on most tools and figure out what's worth buying.
I also worked on my own bike for well over 30 years before I acquired a bike stand (given to me by a neighbor who was upgrading). I've built wheels without a truing stand or dishing tool, making do with primitive substitutions. A talented mechanic can make some tools from pipe, angle iron, threaded rod, etc.