How do I get closer to him?

Recently I met this guy on a trip with a bunch of people from my grade. I got his snap and we had been snapping back and forth. I ended up inviting him out to get some bubble tea and walk around the city. He came and honestly, it didn’t last that long. I’m not sure if he’s interested but either way I want to be his friend. I was planning on inviting him to my birthday with just a few people on the beach. Would that be too much? Is there anything I can do for us to get to know each other better?
How do I get closer to him?
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