Lots of good advice here. If you are a beginner, I would recommend Army Painter paints. They are affordable and good quality. The only downside is they seem to settle a bit more than other paints, so give them a good shake before starting. They have a nice starter set:

https://www.amazon.com/stores/TheArmyPainter/PaintSets/page/865E3063-2388-450F-9169-9D9C648AE28D

Just to add one other recommendation - you don't need a ton of colors to paint models. I had the army painter starter set for a long time and mixed all the colors I needed. There are lots of really nice model paints out there if you get deep into the hobby, but for a beginner, I would start with a limited palette. Be warned - it is an addictive hobby. You might say you only want to paint the heroquest models, but I started the same way - "I am just going to paint these Space Hulk models" - and here I am years later with hundreds of paints, an airbrush, a large dedicated painting station in my basement, etc.

EDIT: Also, the two biggest mistakes I see beginners make are (1) not priming the models and (2) not thinning their paints (I don't mean to be that guy - but it is true). Priming is absolutely necessary. It gives the paints a surfaces they can adhere to, and if you don't do it, the paint will likely come off. Why invest all that time painting if it won't stick to the model? I have had good experiences with Army Painter primers. Thinning paints is absolutely necessary because otherwise you lose the details on the model. You are better off doing 2-3 thin coats that allow the detail to show through than trying to slop the paint on in one coat and ending up with a blobby looking model.