Stop and take this in. I am serious, remember the anxiety and the excitement and don't let it go.
This is the start of the next four (or more) years of your life and its something that you will never forget. It's something you will look back on in two, five, ten, twenty years. This is important.
Don't feel stressed because you brought too much stuff or because you may have forgotten something. It will work out- I promise, it always does. Don't worry about unpacking everything all at once, you'll have time for that later. Take this time to spend with your family or your new roommates. This is a big day for them too.
If your school has anything like mine did on move-in day then you will have tons of options for things to do for the rest of the day. Do them. Go to the cookouts, do the campus tours, go to Convocation, smile for the photos that your parents want to take. This is hard for them.
When it is time to say goodbye to those who came to move you in (family or friends), make sure you do say goodbye and that you don't just brush them off.
It's okay to cry when you say goodbye- whether you live 20 minutes away or 10 hours- it doesn't mean you are unhappy or regretting your decision, it means you're human. No one is going to judge you, that's your family, and everyone else is either going to go through it too or has been through it before.
Most of all remember that this is the start of whatever you want to it to be. Some will say its the best four years and others will disagree- but it is whatever you make it. So take it all in and do as much as you can (especially before classes start). Make sure to have fun but to also remember why you are here. The next 4 years are going to fly by- trust me the past two have for me. It feels like yesterday I was you. I came knowing no one and nothing about how to live on my own or act without my parents around. It will come in time- I promise.
Best of luck to you and have a great first year!
-The upperclassmen.