Welcome over here!
I'm assuming the ragged edges to be deliberate so how would you display this if sold?
It's a very vibrant painting and those foreground colours are a lovely mix.
BTW - to answer a question you asked in Acrylics .........
I use mountboard a lot for paintings (matboard in US) .... I usually have large-ish bits left after making the windows but I also have a large amount, free, from framers - if you know any, they might furnish you with some!
.... of course, they won't be a big as this above!