how to get lowbie to menagerie?

how early can you get to the menagerie? I thought as soon as post searing but how do I get there?

Probably have to reach LA to get onto the boat.

Perhaps by joining a guild? Not sure if you can travel to battle isles beyond the GH though.

Yes, you need to be able to travel to the Battle Isles to visit the Ziashen Menagerie. Once you reach a port city (Lion's Arch-Prophecies, Kaineng Center-Factions, Kamadan-Nightfall), then you should be able to go to the Great Temple of Balthazar and that will open up the Battle Isles for that character.

Can you just jump there from your Guild Hall before reaching a port city?

joined a guild to give it a try but the map is blank except for the GH, and I don;t see any exits.
Darn, time to get run to LA, I want to swap pets

Remember that you can't charm a pet too far above your level. ANet doesn't want level 4 characters running around with level 20 pets.

No, you have to actually reach one of the port cities on your character to be able to use the ship to travel to GToB, and from there to the other places in the PvP area.