This is easiest to do in a commercial building which has several flourescent fixtures. You can just swap out bulbs with another fixture. If they all work, then problem is usually ballast.
Sometimes new bulbs out of the box don't work. Try replacing all bulbs if you don't have another fixture to swap out bulbs with. Then re-install one bulb at a time to see which works and which does not.
Some flourescent fixtures have "flakey" wiring going to the end sockets. These wires are "pressed" into metal clips which cut into the wire or pushed into a clip which holds the bare end of the wire. Sometimes these wires come loose. I've seen brand new fixtures out of the box with one or more of these wires hanging loose! So like many things I buy these days, I need to fix it to get it to work.