Hi there, I'm new to Subeta so still figuring things out :) I was wondering how to get hold of a background for my avatar. Are there any specific shops that sells these?

There's no specific shop that sells backgrounds. Backgrounds can come from different places, like the Token Shop, monthly collections / the cash shop, or general game prizes, events, but mostly through the shop search purchasing from other users. I tried to send you a cheap background to build up your background collection but you have non-friend gifts disabled ^^'

thats very nice of you, I have changed that setting now, if you want to try and send it again.

I sent it! :D

yay I got it :D

The only regular shop which has backgrounds is the Book Nook. You can see a listing of them here.