Alright /diy/ I need to apply base coat to an indoor wall, then primer, then paint. I have only worked with paint.

How am I supposed to prepare the base coat? Just putting water and the powder in a bucket? What are the measures? How do I apply the base coat? With what should I sand the wall after? Any sandpaper is good?

Now for the primer, the base coat says it is fast drying, but how long should I wait until I apply the primer? A day? An hour? Anything that I should know about primer or I just apply it like the paint? How long until the primer dries and I can move to finally paint?