Yes. I had a sandbox when I was four years old.

Courser grit to finer. Any straight or flat sections should be sanded with a saning block. Hand sanding without a block will round edges, leave dips and rises, and should only be done to form or follow curves.

I have small sanding blocks of 4" right up to long metal extrusions of 24", in several grits. 60grit shapes FAST and actually shapes parts. 150 grit is good for smoothing edges. 220 begins to leave a finished surface. 400 leaves a very smooth surface. 600 gets a very nice finish; and with repeated applications of a sanding filler will leave a surface ready for paint. if I'm covering a model with heat shrink I (personally) sand with 400 and stop there. Wiping with a lightly damp rag between sandings will raise the grain and clean the dust off. Let it dry and sand again.

Have a nice stable and flat work surface to sand on. Use long strokes back and forth WITH the grain. Never swirl and don't cross the grain unless you are removing lots of wood or shaping an edge. Take your time, have good lighting

Sand ribs together and not one at a time. If you do them one at a time you'll have different sizes that will mean you'll have to take more wood off to make the wing smooth when they are assembled. You can also not sand them at all until they are glued to the spars and leading/trailing edges and then sand with a 24" wide block, doing multiple ribs at once.