How long do I have to wait for paint primer to dry before painting?

The label on the can should tell you time as not all paints are the same. Don't buy dollar store rollers. Invest in better quality ones and you can reuse them many times if you take care of them. Wash and dry immediately after use. I wash mine and stand them up to drain in the paint pan or sit on top of the trash can to drain and dry.

Depending on what type of primer you use, ie: oil base or water base and drying conditions... if in a humid room, even latex primer will take longer to dry than in a low humidity spot. Oil primer can take many hours. Latex primer can take 30 minutes. Once it is dry to the touch, you can paint over it.

I use duct tape or packaging tape and pat the roller cover to remove the fuzz.

When dry to the touch