Question for rideshare driver tax prep

Hi,

I am the rideshare driver on Uber and Lyft.

  • What tax forms I would need to fill out and does he need to do the quarterly filing?
  • Why do I have to pay quarterly taxes and how can I avoid it? 
  • How much do I need to pay in quarterly estimated taxes?
  • What’s the penalty if I don’t pay quarterly self-employment taxes?
  • Do I have to pay quarterly estimates to my state too?
  • Is he eligible to do the payments to 401K if he is self-employed?
  • Can we still do the married joint filing together or do we need to do a separate tax filing one for me and one for my spouse?