Hi Shamila
I've done 4 JY trips and have yet to eat alone, people are all there to have a good holiday. They'll be a mix of people that have been before and a few newbies I'm sure.
From my experience everyone gets along great, yes they will split into small groups but this happens naturally and you'll find yourself knocking about with others with the same interests.
I'm sure you wont be alone unless you want to be, you'll have a great time and make new friends.
Mick