Part time work in US

Currently I work full time, volunteer to tutor English twice a week (taking about 2 hours out of my day each time), and take and assist in teaching martial arts classes 3x a week (I assist for free as part of working towards my black belt), so I have a fairly busy schedule. However, I'd like to earn some extra money. As you can probably imagine, I'd like something part time that I can do from the comfort of my home and choose my hours. It would be great if the number of required hours wouldn't go above 15/week, but that may not be realistic. I've read several posts on here about Appen and Telus international. Are these sites my best chances to work extra hours when I can and to do it from home?

My background is in archival work, but is there a way to get a certificate in something like QuickBooks so I can apply for part time book keeper jobs? Are those jobs super competitive? Just brainstorming ideas.

Thank you for any advice