How can I improve my website ranking?

Hello everyone,

I've recently launched the beta version of UI Coach 2.0 which is a platform that helps you practice UI design with features like:
💡 Project ideas
🎨 Color palettes
✒️ Font pairings
and a huge curated list of award-winning and nominated website designs you can browse to get inspired
https://www.uicoach.io
I'm quite new to SEO but I'm used Next JS to build it and I followed all the guidelines my website seems to have pretty good on-site SEO when I used multiple tools to analyze it but I'm still not noticing any difference in search traffic compared to the previous version which had terrible on-site SEO, I'm not sure what I'm doing wrong so any help would be appreciated.