“Is it okay to call the shadchan on your own without your parents getting involved if your 20 years old?”
I’ve always dealt with all my shidduchim on my own, and so have most of my friends, but these things probably have to do with your community and family.
As an American in Israel, I wasn’t part of a community, so I had a lot more leeway regarding these kinds of “rules”.
I guess the questions you have to ask yourself are:
1. Why is it important to you to call the shadchanim on your own?
2. In your community, would it be very looked-down-on and cause people to think poorly of you or affect the type of shidduch suggestions you get?
3. Once you have answered questions 1 & 2, weigh the answers against each other in order to reach a decision.
Personally, it doesn’t sound like a big deal to me, but I don’t know your community and family norms.
Hatzlacha!