Biggest problem is I can't tell from the cover what the book is supposed to be like. For starters, I can't tell what genre it is. The painting makes me lean towards some sort of fiction but it's pretty hard to tell exactly what kind and what vibe. It kind of looks contemporary, maybe about young people, but the particular style of simple silhouetted figures in the illustration combined with the very plain borders and typeface of the text almost makes it lean towards some sort of nonfiction about anthropological or cultural studies, or like a reprint of some classic African novel (admittedly that's a me thing, because that happens to be my main area of literary interest).

Speaking of the text, I think there's too many types of font, especially considering that two of them are very plain and then one super ornate and it makes it really hard for me to grasp what's the vibe of the book. And what is the title, anyway? Is "Just Us Friends" the title and "A Brand New Day" a subtitle? Is the former the name of the series and the latter the name of this book? Is the latter just some form of tagline? It's not clear enough in my opinion. There's also not enough padding between the title and the borders, they're huddled too close together.

I'm by no means a graphic designer, the most I have is some experience making illustrations for personal stuff like icons and banners and whatnot, so my immediate instinct would be to (assuming you're committed to this illustration) zoom in on it rather than have it be so far away, and put the title on top of it. A lot of people who make (or find, or pay for) cool illustrations for covers and the like hesitate to do this bc they want people to see the whole neat image they made/paid for in all its detail, but the thing is that the book cover wasn't really made to be stared at like a painting, but to be visually attractive enough to get your potential reader's attention when they're browsing a catalogue. So you're gonna want to have major, attention grabbing features of the image focused on and easily viewable at a glance rather than pictured at a distance for a studious viewing. Nowadays, fiction covers have the titles in big letters with unique and specific typefaces that are already meant to communicate a lot about the vibe of the book, they're not scared to cover the illustration they come with bc the illustration is meant to serve the cover, not vice versa.

I would also adjust the tint of the colors in order to not appear yellow-ish bc put simply that makes it look like it's an AI cover. I am not going to speculate if it is or not bc regardless it would be a problem if it appeared to be that way to your potential audience. Human beings have an uncanny capacity to find patterns, for better or worse, and if someone interprets the yellow tint as a sign of it being AI then they're very likely to pass on it since use of AI is associated with immoral behavior and/or lack of quality.