Thinking about becoming a SEO Freelancer

Any SEO Freelancers in the group? I`m learning about SEO and thinking about becoming a SEO Freelancer. I want to know if it is possible to earn a full time income this way? What are the ways to earn money doing SEO freelancing? I`m guessing that the first way is to make a website about my seo service and try to rank that website to the top so people and companies can find and use my seo service. Is this a possible way? Would my clients limited to my own country or would they be internationally? The other way I can think of is to find work through Upwork. How hard is it to find work there? I heard that some people could earn a lot by just freelancing through Upwork, is that true? The third way I can think of is selling a seo gig on like Fivver or other online marketplaces. But in Fivver the gigs are very cheap so I don`t earn much. And most seo gigs on Fivver are not that effective. So maybe there are other better online marketplaces were you can provide high quality seo services and charge a bit more? Above are the 3 ways I can think of on how to be a seo freelancer. I`m not sure if they really could work out? Or are there other ways to be a seo freelancer and earn a full time income?