Hi friend,
I've just gone through your post and I really understand what if feels like to try out mediums or materials and see them not responding as one expected nor wished but in this case, I would advise that you size your cardboard with glue/gum and allow it dry well before using acrylic paints on it.
Dear,
You refer to glue or impregnate the paper before with glue paste. I do not have that material. I have seen that they also use other things (liquids, or paints). I am still researching on the subject. In Cuba it is complicated to find something. I would like to know specific things that you think I should focus on. Keep in mind that these are my first three attempts at art. We'll see if I manage to get better materials and keep trying. Trial and error. Experience that accumulates.
Can you locate an art store within your vicinity? If yes, I'll advice you check in there and buy "Gesso", you can use that to prime the surface of your cardboard and paint on it after it's dried.
Everything here is an informal market. There are no such stores. At least not in the whole province. It is complicated. What you are referring to is a type of paint, it is a glue. Do you have a photo of the product?
Don't worry about it, you can use any glue that is water based to size your cardboard and start working on it once it's dry.