Possible problem manifest.json is request my username twice

(edit below)So I’ll try to be short as im typing with half-closed time

I spent 9hrs trying to make this work:

and it shows just blank page

I tried to create different repo’s with similar name and fix that then fix that… it’s not loading on either, i hoped to learn coding and all i get is 90% of my time goes into github as if it’s rocket science

so after 9hrs wasted, i also noticed (ctrl+shift+I) it’s trying to pull some link like:
So it goes like username.github.io/USERNAME/gh-page-name

While compared to my other project from few months ago = it pulls just username.github.io

and also the mentor’s app which is identical to mine doesn’t pull username twice.

I’m not sure what is messed/ is missing that caused this problem

Is .gitignore causing some problems

I’m not trying to re-write my whole project, but i may perhaps try new create-react-app and copy-paste the rest

or was something wrong with repository Name?
Should I call it USERNAME-my-project-name

is that username necessary? as in my previous project I didn’t have it nor I want my username in the project-name as previously it worked username.github.io/whatever-project-name

Edit: i made it work on new repository:

I’m not sure whether: wrong “homepage” link > Npm run build > edit correct “homepage” link" (add/commit/push) > Npm run build
was causing problems or not?
Meaning: I had to have the correct “homepage” link from the very beginning(before the Very 1st Npm Run Build) ?