what can I do to avoid default?
You need to fully understand your loan agreement and the types of loans you are receiving. Don't borrow more than you need or more than you expect to be able to repay.
what happens after I miss a payment or two?
Your loan will be delinquent and late fees may be assessed. Even if you are delinquent on your loan, you may still be able to avoid default, so it’s important that you contact your loan servicer immediately.