Can you guys elaborate on these points?

OK, I’m trying to get into this as a hobby, so I looked it up on YouTube like any normal person. Most of what I find are voice impression tutorials. But when I watch videos about actual voice acting or making your voice sound better, they just kind of gloss over everything.
One of them mentioned practicing your vocal cords or something like that, but they didn’t really elaborate. Another said to read scripts, which I can see helping. Then they mentioned writing something, which I don’t really understand how that helps. They also said to listen back to your own voice and then try again.
So I guess what I’m asking is: can you elaborate on these tips and explain how they actually help?