Good suggestions! I'll take a look in Girlboss for sure.

I would add another suggestion to yours: writing. The Medium Partner Program is probably the most easy place to earn some money writing about Design. But there's more. There are many blogs and niche websites that need articles and posts about UX/UI, Design, Marketing and everything is between. Learning the basics of freelance writing (how to pitch, for example) come in hand for that.

Thank you for this!