“If you think you are too small to make a difference, try sleeping with a mosquito.” [Dalai Lama]
Excel VBA is a programming language. You can write programs to enhance Excel standard worksheet functionality or to repeat specified actions, for example.
As with learning in general, you might want to look around for all possible material you can get hold of, sort/order/structure it to your needs and filter/focus on parts you profit from most. Some nice points to start at:
(External link!) VBTutor (detailed)
(External link!) TechBookReport (simple, short)
Enter VBA Editor by pressing ALT + F11
VBA Project Browser: Change module name with F4 but do not choose a name of a function or a sub
Record a macro. You will get ‘spaghetti code’ but it’s an easy way to look for a function or for a command you don’t know or you can’t recall. Do not forget to clean this up!