For truing, just use the brakes, tighten the barrel adjuster until it just starts to rub. True that out and tighten another click. Repeat. You can get it to less than 1mm.

I use a ruler or wrench on the seat stays to check radial runout.

Measure from the braking surfaces of the rim to the seat stays for dish. They should be equal.

Do all of these with the tire off. (unless you are just doing a minor truing) I do this by putting my bike on my trainer. It is a decent workstand if you don't mind siting on the floor.