How to not be so awkward around people I don't know well?

I'm really socially awkward at times when there are many people I don't know in a group. I feel intimidated so I usually do not talk and I just listen. I'm going on a camping trip soon with my family and a few other people/families. I know who they are and they know me but I don't really talk to them. I talk to like 2 or 3 of them a lot when I'm just alone with them but in a group I'm just the quiet girl! I'm actually pretty loud and I only become like this around big groups of people that I don't know unless I'm with a good friend that I'm comfortable around. I'm sick of always ending up as the loner. I feel awkward so I move away from the group and end up by myself. I hate being alone and it makes me feel depressed. How can I be less awkward? Thanks:)