I have an approved I-140 and a pending I-485 Application for a GC (employment based 3rd).

In addition to my full-time EAD employment, I would like to start a part-time business, which involves setting up or taking over a small business.

Am I eligible legally to setup and run a business part-time in addition to my full-time employment?

Can I have additional income with the IRS?

Are there any limitations, regulations that I need to follow/consider? Is there for example a limit on how much I can earn?

Which business form is the most favorable and why (C-Corporations, S-Corporation, or LLC)?

Can this business activity be in a different field form the one stated on my I-140/I-485?