Can you give me ideas for decorating this wall (pic)?

Go to amazon and type star decals into the search bar. You will have to wade thru some stuff you don't want but they have a good selection. You could go a different route and try some other patriotic items in the search bar. Perhaps fireworks or eagles.

Amazon also has some nice American eagle decals.

Maybe a red candle a white candle and a blue candle some greanary around the window

https://www.amazon.com/s?k=God+bless+America+sign&ref=nb_sb_noss_2

Remove the lantern from the middle. Add matching lanterns on each side that are battery operated so that you don't have wires showing. If you have to use something with wires paint them same color as wall. Place an eagle wall plaque above the window.

i just want to say how amazing that flag looks displayed behind that door. i would have never thought of that. maybe string lighting behind the wood where it just glows out they have battery operated so you dont have to have wires hanging or even solar

How about hanging some copies of historical documents, or letters. I'm thinking the Declaration of Independence, and a handwritten letter from that era would look AWESOME framed and displayed around your lovely flag! Kuddos on your project...looks great!