It might not be the funnest thing but it's just one evening and it'll pass.
Arab weddings (I'm assuming it's not mixed since you're saying they are conservative?) are fun but they have their downsides.
If it's not mixed, at some point, the groom will come in, either the beginning or end (depends on how the family does it) so be prepared to have your hijab on hand. Since it's not mixed, you may be surprised what you see under those jilbabs/hijabs! Even conservative women, when the hijab goes off, I know that desis are often surprised because even non-hijabis are kind of shocked as they dress modestly because I think it's more ingrained in desi culture. Arab women wear western clothing so ya. And there's probably going to be music and dancing.
At my engagement party, some of my desi friends asked if they could wear desi clothing and I said sure. Most Arabs are used to seeing that now. I think it's cool personally.
If it's a wedding, just be sure not to wear white.
At weddings, people are usually pretty amicable as it is a happy occasion so don't get to shy. I'm sure there will be somebody your age so just sit down and introduce yourself and enjoy the experience
