Is it weird for someone to say "there should be more people like you" after only talking to them for 10 min for the first time as you're saying goodbye?

No, He/she probably liked you and your personality. Nothing wrong with that.

No. I believe that you can convey your character and sum up your thoughts and beliefs in 10 minutes. Even if it is your first time talking to a person. I also believe that by continuing to talk to that person getting to know them in different facets of there life. In the bible, Jesus' disciples got to know him intimately by spending time with him in every day life settings: A wedding, meal time, in spiritual setting. He showed them compassion and taught them life lessons

If you go out and do kind things in the world, or treat people kindly and fairly, then no.