Does working for my parents count as work experience/employment?

Can I put that I help out in my parents’ restaurant as work experience? I do not get paid. Would the job position be called “assistant”?

I’d say you could put that down. If you did work typical of an administrative assistant, I think it would be okay to call your job title “assistant”.

I did an unpaid internship at my dad’s company a few summers before I applied for college, and I had it on my resume that I submitted through the Common App, and everything turned out okay.

Yes, definitely.

Yes you can. I’d probably put something more specific than assistant. Did you wait tables? Create a reservation system? Help with accounting? My son worked for my architecture firm one summer. He mostly did 3-D modelling for me, so that’s what he put down.