Is there anyway to change my username? If so, how? I’m transgender and my user name now is my dead name, and I dont want to loss all my friends on Vrchat.

Go to go to edit your profile and at the top you can change your display name

Special notice it gives

You may only change your name once every 3 months, choose wisely! Once you change your name, you may never be able to get your original name back!

Your display name can be changed every 90 days, as @Butterstuffs points out.

Your user name is the first display name that you ever used, and it cannot be changed.

This might change in the future.