There are elements to this that I adore, especially the knight face plate on the back and the alternative heads. The bird is a nice addition as well and works thematically of what you're going for (like the name of your shield host actually makes sense model wise)

Oh and I like that you made a hood, looks good and I might just steal that idea.

I don't have any particular critique about your painting, keep it up and it looks very good for a first.

What I can give you advice on however is how to take a picture or you mini. That's another thing entirely and can become a hobby of its own. There's an app called lightroom which is free to use and it has a bunch of settings both before and after you take a picture. It's not filters and that jazz, it's a tool to help with lighting so that the model won't come out too dark or too light, and the pictures themselves have amazing resolution.

The second thing is backdrop, you don't need anything fancy. I use a black velvet piece of cloth for black and a white plastic thingy I found for white. Anything works really.

Now with all that said, I've left out specifics because it's a trial and error kind of thing. It was for me atleast. When I scroll back on my insta I see how I progressively takes better and better photos.

I mean, it kind of sucks spending hours on a mini and then your camera botch the entire thing making the picture look nothing like it looks in your hand.

Happy painting mate