I know nothing about this kind of stuff, but I can solder and do electrical shit when the instructions tell me what to do.

I essentially want to have my Arduino to control a bunch of RGB LED strips and bulbs (a combination of the two). I would like to have a rainbow effect, where one color follows the other, I'm sure ChatGPT can make the code for that. LED strips around the outside of my car and some single LED bulbs inside the car.

What I'm confused about is the voltage thing, I'm a dumbass so I can't really make sense of it. I've seen a few videos and it looks like I can more or less have an endless supply of RGB channels if I buy the right boards, but Google and ChatGPT say that voltage is a huge concern.

Let's say I have one Arduino with twenty of those extension boards (I'm sorry, I can't remember what they're called but it's like 5790 or something), how would I be able to control the voltage of those boards so that everything works properly?