Why would you ever "have" to support clients ? That's the main point of freelancing. The client pays you either for a certain number of hours of work or to do

Why would you ever "have" to support clients ? That's the main point of freelancing. The client pays you either for a certain number of hours of work or to do a specific project. You're never obligated to do anything beyond what was agreed on. Repeat work is usually desirable though, because getting new clients is often the hardest part of being a freelancer. As for how big the projects are it varies a lot and anyway my information would be way out of date so the best way to find out is to sign up and see what kind of jobs people are posting. When I was doing it you could often find jobs like building a simple website, a scraper or basic data processing or analytics scripts that could be done in a week or even a few days.