try to look at The Futur on youtube https://www.youtube.com/watch?v=jE53O1PzmNU

TLDR version: you shouldnt charge per hour, look at market rate around you and build you name/brand first

if you think that amount is fair then its fine for couple of new project, once you got the flow and good network with your client then you can charge more, always negotiate everything

lots of open and freelance platform you can check like https://www.upwork.com/ and https://www.freelancer.com/