If you want to get the basics start here:https://www.amazon...s=access+all+areas
It's the URBEX bible.
You're off to a good start so far by reaching out to others but this tends to be a cloistered group of people who are skittish about newcomers (for good reason).
Try doing some explores on your own (Read the Rookie Forum on this site for great advice), take some interesting photos and have a good story. Once people begin to recognize you, your world will open up.
While it's great to learn from others, I've found that experience is the best teacher, so get out there and show us what you've got!