The best place to wait for a party is NOT at the party spots but at Jeuno. The Valkurm Dunes and Bastok Markets are the only exceptions to this(Valk being valk, and Bastok around 15ish for Korroloka Tunnel).

Every party will start in Jeuno afterward, and its best if you dont wait in Kazham. Stay in Jeuno and get invited else you probably wont.

30-33 I think Sea Serpents Grotto is ok vs the Crabs there but you have to get a knowledgable party to be there. Alternatives are Eastern Altepa Desert and Garliage Citadel.

Then you stick with Crawler's nest til 38ish where you have the option to move to Gustav Tunnel if you want. Then you either go Quicksand Caves or more Crawler's Nest. Which is good up til 49ish where theres the last leg of Crawler's Nest or you can go back to Garliage Citadel and exp there before moving into Kuftal or Boyada Tree.

But if you are seeking, always always stay in Jeuno.