I have learnt what I know about Access and VBA almost entirely from the Web. I Google as a I need to know. There is no better motivation than needing an answer for a real problem. Trying to read this stuff from a book is not very inspiring and retention is poor. Similarly doing exercises does not motivate like a real project. Even if it is someone elses.
I found I often ended up here, especially when I started seriously gettng into VBA. The other site I use a lot is Microsoft's developer reference. The related pages list at the bottom of most pages is a great way to expand the subject.
Often the questions I asked here would lead me into a whole new subject so I started reading other interesting looking problems. This introduced me to whole new ways of working and helped me avoid falling into traps before I came to them.
Then I started answering questions when I thought I knew the answer. I did this mainly to develop familiarity and fluency in an effort to avoid having to look up the syntax every time I needed something. The really experienced people here would add to, correct and clarify what I posted which really helped round out my knowledge. I often go and search for the answer to questions I like.
Knowledge infuses over time. Each little piece gathered may make little sense at the time but eventually the edges meet and the big picture falls into place.
The other important aspect is to try something based on what you think you understand. Do what you expect to work and then find out why it doesn't. I have learnt so much by trial and error and coming up with a wrong answer can be really informative.