Correction, you want the outside of your dorm room to be outside of your comfort zone. However, it is more in your comfort zone than you realize.
Halloween is the perfect time to do this kind of stuff. You can wear a mask if you want. Yes you dare go alone. Otherwise you won't meet new people. I am sure you might run into someone from your classes.
Anyway here is what you do. Go to the party, feel free to sit and relax, but don't stay sitting for too long. Make sure to move around a bit. Look for a group of girls and/or guys, walk up to them, tap one on the shoulder and ask a random question. One question I like is the drunk I love you question. It goes something like
Can I get your opinion on something. Last week my friend got really drunk and told his girlfriend he loved her. Problem is that is the first time he has done it. Does that count?
I promise you anything set of girls will have an opinion on that topic. Then just keep the conversation going. It is not really that hard. Make sure to stand up straight, make eye contact and speak loudly. In a place with a lot of loud music you will likely be screaming at them. That is just fine.
One thing that people don't realize is that it is perfectly ok to have canned conversation topics. If you want a topic to approach a group of guys with..... Well I don't really have any. However, you just have to make a comment about sports or ass(Girls in a sexual tone) and you will be in.
Here is your goal for the weekend. Find a party every night and talk to at least one group of people. Just one, you will find that doing that feels really good even if it goes no where.