Remember that just because your roommate doesn’t share the same level of anxiety or excitement doesn’t mean they are bad people. They may not have the same socioeconomic background or family support you do. As others have said, they may be using July as a disconnect from anything college related.
I would send the roommate a message and give them all your contact info if you wish. This means phone number and any social media you wish to share. What your preferred way of talking might not be theirs. Tell them. “Here’s my contact info if you want to get in touch. If you want to coordinate and discuss sharing a fridge or microwave please let me know. I’m happy to bring stuff for our shared space and set stuff up. Have a great summer and see you soon!”