Guy gives me his number without me asking? What to say/do?? Thanks?

[aries24]

hung out with him once before at a casino night at school and saw him at a meeting a club i'm in and he gave me a hug and everything, i think he wanted to talk but i was talking to someone else so he said he'd see me around and said bye.

I'm a sophomore in college, he's a senior it think, not sure. So I messaged him on fb wondering the time of an event for the club we are in, but he didn't see it and instead responded on wednesday:

"I'm sorry for not getting back to you in time! I've been so busy lately and I don't use FB much
Here's my cell phone number for the future: (2-) . Feel free to literally text me anytime about anything. Thanks "

So I haven't replied to this because i mean i have no idea what to say back.
He was at a fundraiser event for another club i'm a part of on thursday, it was at a night club/bar, and he said hey and everything and gave me a hug. Then before i left i saw him again and he told me that i looked beautiful as always, i said thank you and told him i was going home and he said drive safe. I can't quite remember verbatim what he said but i'm pretty sure he said either beautiful or pretty. lol idk.

Question: what to say back to him giving me his number on fb message since i still havent responded... and what does that mean?

[whyskyhigh]

let your mother answer

[Doktor Evil]

Don't overthink this. Just txt something like "hey! Wassup?"