How do I file taxes when I don't have a job, but still have money coming in?

So I quit my job back in May, and I now live with my girlfriend who works part time. I've been making ends meet by having money gifted to me in the form of crypto from my friend, which I then sell for USD. I know about crypto taxes, so that's not my main question.

 

I've been using Turbotax for over 7 years now, and so this is quite new to me. Am I technically self employed? What taxes do I have to pay now and when? Is it quarterly, or do I still file before April next year?