Management exp 0/10, coding and idea 10/10, should I do startup?

I think with stats like that I would feel so confident in coding and ideas that you should then be completely comfortable now devoting all your time & effort to the most needed "business" part of the business if you really want to go into business yourself.

Start building your idea on the side while holding on to your current job.

Find customers.

If you start getting paid customer traction, start looking for investors (optional; you can choose to be self-funded).

If you have reached this far and cannot manage this with your current job, quit it to focus on your startup full time.

Bill Gates had no experience of being CEO when he became one.