worked in 2 states should i file together?

Answer 1

If your residency was continually in one state you only need to file once. For example, when I was in college, I worked in the state that I went to school in and in my home state, but was able to file all of my workplaces onto my home state tax return because I was a resident of my home state the entire time.

Answer 2

federal income tax...yes
state income tax...no