Before the squish you had to be 110. Of course, before the squish you had to be 110 to go to Zandalar/Kul Tiras so it made no difference. Now you can level up from 10 to 50 in the BFA zones. And the faction incursions (one every 16 hours) are good XP.
Now you have to be level 35. And you need to get 100 War Resources. Then you can unlock the first assault mini-chain (15 minute questline), and have a permanent link between continents.
Since you can fly at 30, you only need 1. You can fly to the other 2 zones.