So night before last, I had a dream where I saw two people I didn't know. They were just chilling and then they kissed. The guy had brown hair and the girl had blonde hair
(My boyfriend has brown hair and I have blonde hair) But I didn't recognize them as me and him. They were older like 19 or 20 .

Last night I had a dream those same two people were getting married. And I've never picked up on names, it's like it skips over it. What does this mean?

Your dream could be about you and your boyfriend. A secret about dream interpretation: if it feels like someone you know even though their appearance is different, it probably is that person. Dreams often put a symbolic spin on appearances, whether it be a person, place or thing. The reasons can be quite varied. Here are some links to the definitions of the symbols in your dream to help you understand why you had those dreams:

old (as in older): dreamdoctor.com/dream-dictionary/definitions/old.html
marriage: dreamdoctor.com/dream-dictionary/definitions/marriage.html

Dreams are expressions of your feelings about your waking life at the time of the dream... they aren't psychic, but they can come true depending on what you want and/or allow to happen.

Hope that helps!