Painting basement wall (shell construction)

Hello everyone,

we received our screed a week ago and before installing all the technology in the basement, we would now like to paint the room white.
What do I need to consider for this?
The walls were built with Poroton and so far the rough unevenness has been evened out and a thin layer of slurry plaster has been applied. Next, we would plaster the chased-in cables and boxes with electrical plaster and then paint white. Do we need a primer or something similar?

I am grateful for any tips.
Uploading pictures is unfortunately not working at the moment ;/ will be provided later if needed

You will definitely need a primer, otherwise the paint will absorb quickly! Use good paint and primer, if possible professional quality. The hardware store paint is only suitable to a limited extent for new coatings.

I had thought it like this: To cover the electrical lines with plaster and spray the walls with primer. When everything is dry, paint over with white. Do you need a different primer for the ceiling (which is a precast concrete ceiling) than for the red Poroton bricks? We will not use cheap paint. Is Alpinaweiß from the hardware store already something reasonable?