Unless you go the hand-tool-only route, the necessities are a good speed square, a drill, a good set of drill bits and a circular saw. Together, those three things (cordless Ryobi are great for beginners and not super costly) shouldn't cost more than $150? From there, spend as you like to make projects a bit easier. My shop has gotten a lot bigger over the last year or so... I've spent quite a bit.
My first real project was a series of planter boxes made of cedar 1x3 boards and cedar fence posts. Considering the cost of the fence posts (cheap), it was a great project to not have to worry too much about material waste.
Classical guitar. Bought a guitar. Took lessons for a decade or so and then just kept playing.
If you want to get started look into the rider training program for your state to get licensed, insured and to buy a bike. Even if you aren't in the SF Bay Area, BARF is a great place to start and get your questions answered. Cost is up to you but you can get into the hobby for less than $5000.