2Pcs Rubber 7" Empaistic Wood Pattern Painting Roller + 3.9" Graining Painting Tool with Handle

I am looking to refinish our basement. Concrete block walls and poured concrete floor. Good idea or not?

To use the roller How do you thicker the paint?

How do you use the blue smaller item (not really a roller). I cannot figure out have to get the grain from that one? Thanks all.

Has anyone used the same color as their base coat their top coat? How did it turn out? Or is it better to use two different colors?