Convicting you of a crime is not possible. But there are many, many ways in which you can be screwed, from forcing you to spend a weekend in jail to having a prosecutor offer you a plea deal that you can't risk refusing.

The police have a lot more power in any encounter, and there is no way to avoid having them make your life worse. About the only truly concrete advice is that if you are guilty of something then you absolutely, positively must get a lawyer before saying anything at all. The magic words are “I will not answer any questions without my lawyer present,” and any variation from that exposes you to the risk of the police creatively misinterpreting you.

The magic words can help you beat the rap, but they cannot help you beat the ride. If they decide that you are going to jail, then you go with them, and nothing you say or do (or not say or do) will prevent that. And you will stay there until your lawyer shows up.