Hey there,
What you have to remember is that everyone is in the same boat as you. A lot of people will have never been away from home for any long length of time, and some do struggle with this. My best piece of advice is to be open and friendly when you arrive and get involved with as much as you can. This will keep you occupied and soon youll settle in, and feel at home. Take some things that will make your new room feel like home, and dont let your family stay for too long, just get stuck right in. You can probably already buy tickets to the freshers nights out - do this - even if its not your thing its a great way to get to know people.
Dont forget that with things like skype its almost as good as being with that person now. And also it can help to have your next trip home planned - then you can be counting down to it - but I wouldnt go home too much - it can just be harder for you.
My final piece of advice is to enjoy your holidays before you start uni - spend some time with your family, and learn to cook a few meals if you cant already.