[otaviogood]

Like many have said, start with Arduino-like boards + servos. You can get servo driver boards that let you plug in multiple servos to your Arduino without power problems. Get those from Adafruit. Then you can graduate to the "bus" style servos like Feetech if you want to load up on servos.

If you want to learn to make PCBs, this tutorial shows you how to design them in open source software and then get them made cheaply (highly recommend): https://www.youtube.com/watch?v=PlDOnSHkX2c

Get a CAD program like Onshape (I love Onshape). Learn how to use it to design 3d printed components. Get a 3d printer. Maybe Bambu Lab. Now you should be able to make nice form factors for your robots. If you want to graduate from 3d printing to Aluminum, then you can send your designs to a place like PCBWay or JLCPCB and get the aluminum parts reasonably cheap.

At some point when you want to make a more "real" robot, read this guy's thesis and try to understand almost all of it: A low cost modular actuator for dynamic robots https://dspace.mit.edu/handle/1721.1/118671 It goes over so many things that are useful, like types of actuators, how they're designed, controlled, etc. I wish I had read that earlier. Then if you want to make something like that, I highly highly recommend MJBots. https://mjbots.com/

Make something amazing!!!