I can only speak to low-to-medium security California prisons, but here’s what I know.
Firstly, unless you’ve got a sentence of 10 years or more, you’re probably going to end up in a Level I or II prison, like I did. First you’ll go to Reception, which has inmates of all different security levels, but it’s highly regulated in Reception, and you’re in your cell 23 hours a day, so you’re not likely to have the opportunity to get into too much trouble, especially if you’re new and don’t have some sort of problem already with somebody you meet there.