Speaking generally, $20K in debt is not very much in the grand scheme of things. Your first house will likely put you well over $100K in debt, after all. $20K is more like a car loan, which should be quite manageable.
Debt collectors may not: Use false names or statements, such as falsely implying that they are attorneys, government representatives or credit bureau representatives. Threaten you or your family with harm. Use obscene words when talking to you.