so i'm in love with this hair on my avatar but I can't find anything to go with it so what do you think goes with it best??

Welcome to subeta ! <3

Do you mean something like a hat or a headband? Or do you like to go more fancy, like a fascinator?

like clothing shirts, dresses etc

Anything Purple or black with purple accents will look nice you could search for Purple, Amethyst or Plum in the wardrobe make sure you have "All Items" toggled so it shows you everything, and maybe "Hide CWs" those aren't always easy to get there are a lot of items that you might like

alternatively you can look for site items in the Item Directory here are links! Item Directory: Purple Item Directory: Plum Item Directory: Amethyst

of course there are loads of other purple items that have other names but i think this is a good start!