Im connected to my network but no Internet.

There was a recent power outage in my area and after the power came back, my Internet won't work. Just like I said in the title, I am connected but there's a little exclamation mark next my connection strength and It will not let me use the actual Internet.
This problem is the same for multiple devices, including different smartphones and computers.
I have tried restarting the modem/router (not 100% sure which is which, I only have one box), and doing a factory reset.
I cannot log into my Internet's portal because my roommate set it up and hes out of town. User and password are not "admin".
Can anyone please help me?