Furry meet ups aren't anything particularly scary, a lot of furries are shy and nervous so you'll fit in with the group fine. Here's a couple of things I suggest you do!
1. Before the furry meet up see if you can meet some furries online who are attending. It might be good to have at least one person you know at the event and they can introduce you to all their furry friends and you can become one of the group!
2. Introduce yourself as new! Furries love to make new friends and there's a lot of furries who will gladly show you around and introduce you to the pack. The thing is, some furry meets can get a bit cliquey but when you introduce yourself as new a lot of people are more willing to open up and invite you into their group.
3. Know some fursuiting etiquette. Fursuits are expensive, they limit vision and a lot of people can make mistakes when it comes to dealing with a fursuiter, so read up on some proper fursuit etiquette so you don't embarrass yourself. Don't hug a fursuiter without their permission, for example, and don't be rough with a fursuit as they can sometimes be very fragile. Keep in mind fursuitters have low vision they may bump into you if you run up to them too quickly. Don't lift or tug a fursuit tail without permission and so forth. Just general stuff like that.
4. Have a way home. You will most likely really enjoy your furry meet up, but because you said you're shy and nervous you may become overwhelmed, and if that's the case going home is totally fine. Just make sure you have a way to get home incase anything happens.
Overall you'll probably have lots of fun!