Living History Museum in Capital Cities

Im a returning player to WoW and I want to go and briefly experience old content I missed and have forgotten about.
For the life of me I can’t work out how to get to all the historical zones, and have quests available.
If found it extremely confusing and frustrating so I just cue for dungeons to level.
I thought if Blizz created a “Living” museum in SW and Org we can pick the expansion and at lest sends us to the first quest to get the ball rolling.

Perhaps there is a similar mechanic I haven’t discovered so Im very interested in learning how to the expansion zones of Legion & BfA of it if anyone knows?