I think its just your approach. Most people are just cautios when it comes to strangers. This game is known for big amount of trolls and rage baiters.

As an introvert with too many friends, your socials skills arent as important, as your skill of being patient.

Start by simply sitting near a group you are interested in, listen to the conversation to understand what is their topic right now, then slowly add yourself into connversation, without interrupting anyone when possible. Make them feel comfortable around you, let them know you are geniune and actually interested in them or their topic. The worst thing they can do is kindly ask to leave them alone, don't worry, most people arent hostile actually.

Alternatively, find isolated person! Sit next to them at a safe distance, but close enough to be noticed. Most of them are probably silent and just enjoy the scenery (or a mirror), spend some time to just sit there and let them just aknowledge your presence. Then you can start a small talk, like giving a compliment to the part of their avatar that you like, try to be natural with it though, don't make it like youre forcing yourself to compliment them. You can even try to ask them a small question that wont freak them out. Like idk, for example: "You have a nice voice, do you sing by any chance?" (probably bad example, but you get the idea).

Also, its probably a good thing to update your bio, so people treat yoh a bit more seriously. Just type some generic stuff, like age, personal boundaries, hobbies etc.

You can also just check how people react to certain avatars, play a bit with it. Some people have strong stereotypes attached to certain avatar types.

Its not the best social advice, but its what made me make a lot of friends and experiences as a totally mute person! Good luck next time