Chris,
As a relative newbie, it can be somewhat overwhelming. I, too, started with Shackleford's Grounds For Golf. It has the basic concepts, covers the main eras in US design, explores a number of iconic holes in detail, and provides a frame of reference for much of the discussion.
Next, I made it a priority to get to better courses. I accepted invites on here, from strangers, to courses involving long car drives. I used time off. When traveling, I ask here for advice. I take extra early flights, or red eyes, to fill in a round. I let friends know that I am interested in courses, should an opportunity arise.
I don't, however, send PM's unsolicited to GCA members asking for access. That is crass.
Finally, I follow my interests where they lead, listen as much as I can, and try to remember to make up my own mind. Do that, add some value with a well written post, and you'll always be welcome here.
Welcome!