How do I get out of this situation?

Well, my older friend is pregnant and asked me to be a godmother along with her brother, cousin and the babys dads sisters. I was really happy when I found out she was going to be mum and said yes to being its godmother but the more I think about it now the more I dont wont to. Firstly, we used to be really close, like sisters then we drifted apart and didnt really speak for about a year, then she asked me to be her babys godmother. I still havent seen her or talked that much since she told me she was pregnant and asked me and shes having the baby in 10 weeks. Also, i'd feel awquard because all the other godparents are direct family and am only a friend and I dont even know how to hold a baby properly! I also really hate audiences and big social situations pretty much and I would have to stand up infront of all their family at the christening :( I'm a 14 year old girl and shes 22, if it helps. So what should I do, should I be the babys godparent and go to the christening and act all social even if i dont want to and get close to my friend again and her baby or make an excuse but still go to the christening? If you say make an excuse please could you say some excuses. I feel really bad I like my friend and happy that shes pregnant and everything I just hate social places and dont really wanna be godparent cause i dont think I'll be a good one and also because i havent spoke to my friend in ages aswell. By the way she hasnt mentioned me being a godparent since shes asked me, am not surprised really, am not a nice person :/