Just a tip: You should never make, like a full-on copy of someone’s else’s UI (in this example NewFissy), You should always make it unique. I like it tho!
WOW. Looks amazing. Wouldnt change a thing. Not gonna lie you should start charging robux/money for your work. No way I could tell your new to ui’s. Mabye try experimenting with bigger boxes such as menus?
One suggestion I have is for the two icons for Family and Friends: you should keep the art style more consistent. All the characters in the Adopt Me GUI look the same (large head, V-neck, simple shading, etc.); your icons for Family and Friends each depict three characters holding hands, yet they look very different in each. Find a different way to differentiate the two icons. Other than that, I really like your first GUI!
I belive those are free icons provided by canva. Adopt me has artists making their icons, so its hard to customize and keep a theme. I do agree with what you are saying though.
This is an exceptional starting point. I’m a more modern person myself and I love what you’ve done. Sleek, simplistic and easy on the eyes. Keep it up.