How hard is it starting an E Commerce site from scratch?

I want to create a e commerce site specializing in certain clothing items and sunglasses, however the issue is I have no idea where to start. I’ve done some research but I need some advice on the steps I need to take to start. And for people who have a site themselves how long did it take before you started generating a decent amount of sales off your site?

I should add I want to do this for as cheap as possible and don’t want to end up paying over 200 for a domain hosting site or anything like that.