My EB3 Green card date became current - No Green card application with current employer

My Eb 3 Green card priority dates became current (July 2013). However, I do not have a Green card application filed with my present company. I have one year left on my current H1b visa (July 2022).

  1. Can I change to a new company now, and apply for a Green card? and get 3 year H1b extension?
  2. what are the possibilities of my H1b visa get extended, if I file an H1b visa extension with my current company?

Yes, your H1B can be extended under AC21 beyond the 6 year term with an approved I140.

Same as above., even if your I140 is from previous employer.