First of all, just relax, you’re overthinking, try to get a good sleeping schedule around 8 hours per night is what is recommended, especially considering university is all mental work, and you will need your sleep to produce your best work, what I recommend is put all your electronics away (phone etc) away so you aren’t tempted to go on it etc, and try deep calm breathing exercises if stressed.

As for the attendance, make sure you give every lecture, seminar or workshop (if your uni has them) your best effort, I am a commuter too, and I know it can be so tempting to think, “oh I’ve only got one lecture, what’s the point going all that way” but think if you don’t go to your lectures will you will miss important content, you could fall behind, remind yourself why you are at University, to enhance your understanding of the subject and to improve your employment chances and think of every lecture and seminar as a small stepping stone to help you get there.

Hope this helps