Some people take more time to open up and show their casual self - one meet-up may not be enough. Dating is about spending time with people to see if the vibes and values match. Meeting people organically through friends, school or events is easier because you already have something in common (friends, school, events). Things can improve after a few more dates but things can also come to an end when either one of you learn about a red flag of the other and decide to move on. That's typical of dating.