>>396437846
My advice there is to find a base you like and start by putting it in blender. Familiarize yourself with it and how anime girls are put together, and then upload it and start from there. You don't need to do a full on custom outfit to start, just start simple and work from there. If you take the time to learn how to at least do basics in blender, it will serve you well. I don't understand how people get away with not knowing at least the blender basics, unity only is so limiting.
Also, there are a lot of people here who know blender and unity pretty well at this point, don't be afraid to ask for help. Even if it's a stupid question. I've spent hours trying to figure out how to do very basic things in blender in the past.

As for creativity, I think it's good to take some things you like and make them into themes. My avatars always have certain themes. Pick colors you like, maybe an accessory or two that you like and put them on your avatar. For starting out, I think just a couple of things is fine.
As for outfits and such, I follow artists on twitter and take a lot of inspiration from the things I see there. Anime artwork can give you lots of ideas.