Great idea. This is how I learnt to code when I was young. If I found a cool or interesting website that I liked, I'd have a go at cloning it by copying the frontend exactly and writing the code for the backend myself.

I eventually even started selling some of these websites as turnkey scripts for a little while, so others could buy them and setup their own version (often in their own language for their country). Supporting and updating/bugfixing these was eventually too much for 15 year old me so I stopped.