Hi aggie,
one thing I did when I was new to Painter was to create a category of very simple brushes.
This category I named laboratory. Painter’s abundance of literally hundreds of brushes can be both intimidating and confusing at the beginning, so I decided I would do with three or four simple variants to get accustomed to everything.

In there I initially placed a hard-edged round brush and a soft-edged round brush. No impasto, watercolor, liquid ink or other fancy stuff. Just the basics. Should you want to create a category of your own, too, you can simply paint a category symbol on a small resolution canvas (300 * 300) and select all (ctrl+a) and then choose “capture dab category” (direct translation from the german localization, I hope it is the same in english) from the brush selector menu. You then get a dialog where you can specify a name for your new category and then you should be able to create new brushes in there using the brush creator/designer (ctrl+b), e.g.
For blending, instead of using a specific blending tool I used a soft-edged round brush with which I put down the paint/colour. The soft edge provides a fade-out area on the outer circle of your brush dab which can be used to blend colours into another.
Many people frown on the usage of soft-edged round brushes, because they fear that your painting will loose any distinct edges, but that is because they probably don’t mind that you can always change the brush size (very conveniently so by ctrl+alt and then click dragging, btw…
). That reduces the outer fade-out area and gives you a wide variety of edges you can choose from.
If you want to create a brush like that choose
brush property window->general->dab type->circular (or round?, damn the localization!)
then go to the size section of the brush properties and choose the following dab profile…

Think you can see the selected one. Make sure to play with the others so you see the effect of each of them…
here’s a comparison of hardedged round and soft edged round

you can see that I changed the brush size to rather small on one area on the left side (where the softedged strokes are) and that those little strokes have a different edge.
Apart from that, noone hinders you to change brushes while painting…
But I just thought it might help to cut down on the variety of Painter’s brush library to focus on some simple basic brushes. I found it useful at least, but everyone has different approaches.
I painted the complete face of this paintingwith softedged brushes, e.g., and while I can see its weaknesses, I have still fond memories of it, because I sort of had a breakthrough on blending with it.
keep going…