I am curious if I need a business license to operate an online store that sells general merchandise?

I live in Arizona (County = Graham; City = Safford)

Is there anyone that knows for sure what I need to get? Do I need a DBA (Duing Business As) license, a Tax ID number, etc.

Also, do I just charge tax to residents that also live in Arizona?

I realize these are questions for my tax advisor but I was curious if anyone has already gone through this from AZ?

Thank you,
Steve