It's tough to predict the future. Most people don't start wanting kids until they're older than that, or at least until they're in a serious relationship. Given that you did not mention one, I'm going to assume that you are unattached. Most single people in their twenties want to get laid without having kids.
You may find that a vasectomy is a complete blocker for certain relationships. However, if you truly do not want kids, those would be doomed regardless.
Will you change your mind? Perhaps. Many people's views on the subject change as they enter their 30s. But that doesn't mean yours will.
It might also be worth considering why you want a vasectomy right now. If you are single, you should not be hooking up with random people unprotected. If you are in a relationship, this is something that you should discuss with your partner.
This is terrible advice. Ask any urologist and they will tell you the same. OP, ask YOUR urologist about it.
Vasectomies can, in some circumstances, be reversed. You should not plan on yours being one of them. You should plan on it being permanent and irreversible.