All completely normal, everyone has grand expectations but you all forget that you are all living away from home for the first time, trying to take care of yourselves and learn how to interact with these strangers you now live with. It's a weird situation and it's completely normal for everyone to be a bit awkward. As awful as it sounds, bin whatever idea you've had for what you expect uni and all this to be, because it won't be exactly what you expect, as with most things in life. If you can forget expectations and just live in the moment and accept everything for what it is, you'll be a lot happier.
You'll find you'll probably get on better and easier with your flatmates in a few weeks once you're all settled and starting to get busier, but it's ok if you don't become besties with them either. The people you've been allocated to live with are just strangers who happened to be allocated the same flat, you're all different people and it's highly unlikely that everyone in your flat will get on like a house on fire. If you do, amazing! But there's nothing wrong with having a relationship that involves a chat when you happen to be in the kitchen at the same time, or a smile if you see each other at campus. Don't try to force anything, friendships will form. You'll make friends at societies and on your course, so see if anyone you've already met will go with you, or tell your flatmates that you are definitely going to this thing and then they might be more confident in saying they'll go. Everyone's nervous, so if you can be a confident yes to social things, others will be more inclined to also go if they know you, a familiar face, will also be there.