Self- employed quarterly taxes

Hi, I am a self-employed contractor who has to file quarterly taxes. I haven't yet done so and have been working my job for close to a year. I would love some assistance/help with the following questions:

  • 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?

Thanks very much,