When should you meet your boyfriend's parents and friends?

There is no general rule to when you should meet each other's parents. Friends is something else. Friends should be anytime.

Parents however is something else. Unless you end up meeting them casually say , you live next to each other, then meeting each others parents becomes more involved because it actually signifies a step in your relationship.

I am way older past your age bracket and meeting a girls parents usually signifies a certain commitment level within my relationship. I would think that applies to your age group to a certain extent as well.

So I would say, the right time to meet each other's parents is when you are no longer just dating but are on the serious level.