as a freelancer, you get paid hourly. Still, don't bill every minute. it's okay to not send a bill sometimes.
I work as a full-time freelance coding tutor. Hire me at UpWork or Fiverr or Stack Overflow or GitHub. see my personal website. see my photography art hobby at Behance and Unsplash and ArtStation. Also, podcast about life. podcast about movies. and Twitch. and YouTube Channel.