Saying this in the nicest way possible, people will rarely just gift you locations for nothing. Drains, probably. Abandos, possibly. Rooftops, almost never. Between urbex politics and a certain degree of secrecy that surrounds the locations and people in the urbex scene it makes your request extremely unlikely to be fulfilled.
Best advice I can offer is to keep going at it solo, over time you'll start to accumulate contacts and places. Knowledge opens doors. Literally. It's as much about what you know as who you know.
Good luck.
Wander often. Wonder always.