Side hustles/certificate jobs

What are some side hustles (excluding surveys, user testing, faceless/digital marketing, Etsy shop and Fiverr because I've had no luck with those that I can do from home to earn some extra money? I would like to earn an extra $500+ a month if possible.

I'm also interested in taking certificate courses, but which careers are open to accepting applicants with no degrees, just certificates? And which certificate academies or sites are best?

Thanks so much!