1.
If a door, room, or path leads off a place or leads off from a place, you can go directly from that place through that door, into that room, or along that path.
There were two doors leading off the central room...
The treatment rooms ~ from the swimming pool...
A corridor led off to the left.
PHRASAL VERB: V P n, V P from n, V P prep
2.
If someone leads off in an activity, meeting, or conversation, they start it.
Whenever there was a dance he and I led off...
Boren surprisingly led off the most intensive line of questioning today.
= start off
PHRASAL VERB: V P, V P n (not pron)