Do you need to make an appointment at the Apple Store?

Yes

I would recommend that you make an appointment

I recommend it. Ok to walk in for simple questions but if you want help with anything complex or expect they will next to change hardware, i would get an appointment. The web page makes it pretty easy to make an appointment.

Nah. You can just walk in. It's busy, though. So if you can make an appointment, you may want to.