It's actually not that hard:

The formula: number(Optional) action movement

Examples:

2 dl - delete two characters right

dw - delete a word

yb - copy back a word

y/foo - copy to the search foo

4cw - change the next four words

actions: yank(copy, delete, change)

movements: /(search), t(til character), f(to character), many many others (l, h, j, k, *, #, T, F)

Combine as you see fit.