These are two commonly confused words.
So, to meet is to meet somebody for the first time. Somebody introduces you or you meet that person. “Nice to meet you.”
MEET UP WITH: Get together with that person (i.e. hang out, romantic date, business meeting)
RUN INTO SOMEBODY: Meet them on the street without planning (also BUMP INTO)
Know, on the other hand, is when you have a general knowledge about information or if you know somebody, so, you’re familiar with that person, or that place.
COMMON MISTAKE: “I knew that person yesterday” (it should be “I met that person”)
So, for example, “I know Harry very well. I met him at college. I’ve known him for 2 years.”