Choose the paint for your project.
Clean the concrete wall surface.
Repair any cracks, an blemishes in your wall using concrete patch.
Check the wall before painting, for moisture.
Seal the concrete wall.
Apply a coat of concrete primer.
Paint the wall with concrete paint.
Roll on the concrete paint sealer.

Paint the edges with a paint brush.
Then; use roller for the wall area. Make roller application like a vee shape; and then, spread vee area, up and down.
Use paint brush with heavier paint on it, to push paint into any crevice areas.

Use regular type applicator paint brushes, and small touch up brushes, painters tape, paper towels, ladders and drop cloths.
Before painting with roller prime it; by wetting the brush then ring it out, by rolling it on a wall to remove water. leaving the nap slightly damp.
A damp cloth is good to have to remove drips off other surfaces. Some areas need a drop coth, where there ia a surface border area. Mask off and cover areas, when needed.
Paint surface should be power washed, or rinsed off, and broom brushed and rinsed; and bad loose rough paint should wire brushed, off. A paint roller extension pole could be used with higher and lower areas.
Apply paint narrow areas and corner edges with a brush. Then use a roller for wider areas. A second coat makes appearance much better, and only uses about 1/3 as much paint; and the paint last longer.
The left over paint could be used for touch up; or to use to refinish areas.
To store the unused paint wipe away or remove the paint residue build up, that around the can lid cover and can edge, then close lid and tap with a mallet, or a hammer with a wood block.
A higher quality longer lasting paint is better to use; and sometimes it's easier to use it.

Thicker naps, up to 1" should be used for rougher stucco; but, thicker napps drip more.
More paint and more pressure, helps to make stucco look good, when it's completed.