The age difference really doesn't make a difference tbh. It's only a year. I've been through a similar situation where I was a year older than my class, but I didn't feel any different because honestly there isn't much of a difference in maturity. I wouldn't worry too much about being shy either, there will always be nice, outgoing people who will approach you first. I used to be pretty shy too and just let other people come and say 'hi' first. Trust me, it's not that big of a deal. You're just a bit nervous of the change. It'll pass, don't worry.