HTML SCSS AJAX JQuery

I finished this challenge in a messy way I know. but I need some feedback, Questions:

1. I made a container but I ended up not using it Should I just use ** Bootstrap Container ** to make it easier for all screens?
2. my first time seeing System Design is there a guide for implementing it correctly.
3. This Question got me thinking a lot, is there a ** guide for dealing with animations in JS especially when fetching it from JSON or AP I**.
4. I used ** div ** a lot in places where ** there was like what it seems to be h3 then h2 tags and I think using it that way is wrong is there a good approach for that **.