The waterpump probably comes with it's gasket (O-ring).

I re-use the valve cover gasket a few times until it starts getting hard & brittle. If you don't get a valve cover gasket you aren't gonna waste tons of work by changing it later. VC gasket is really easy. DON'T overtighten the VC hold-down nuts.

There's rubber grommets under the 8(?) valve cover mounting nuts. There's a rubber ring gasket for each of the 4 spark plug tubes. Sometimes they're all included in a VC 'gasket', sometimes not. Ask when you order it.