I recently got started and as others have said, it helps to have some idea of what you want to do, since 'robotics' is such a wide field. In my case I was curious if I can get LLMs to drive a robot, so I bought a quality, mostly-assembled chassis (https://www.waveshare.com/ugv-beast.htm) that let me focus more on software and sensors. If you want more low-level stuff, you can make your own chassis (motors, 3d printed parts, arduino/esp32 programming), you can make your own attachments to chassis like the one I have, etc. On the software side, you can focus on navigation/mapping or operating actuators on a stationary base, you can run small specific models (segmentation/etc) paired with classical algorithms, you can run VLAs (LLMs that output motor actions instead of words). There's really quite a bit to do.

I wrote a bit about how I got Gemini to drive my rover here, it might give you some ideas of what the software side looks like: https://martin.drashkov.com/2026/02/letting-gemini-drive-my-...