Hi, and welcome to Azeroth!
The way levelling is currently structured is:
Level 1-10: Your racial levelling zone or Exile’s reach.
Then
Level 10-30 All the Classic zones in Eastern Kingdoms and Kalimdor
or
Level 10-60 Any of the continents from any of the expansions
Any set of zones in one of the continents of the expansions gives enough experience to get one character from level 10 to level 60.
And then, Level 60-70 is Dragonflight.
The enemies in Eastern Kingdoms and Kalimdor will not level up above 30, and at level 35+, as you see, you become Godlike to them.
What you want to do now is go say hello to Chromie. You will find her in Stormwind, under a tree in front of the Stormwind Embassy (you will see iton your map) near Stormwind Lake.
Chromie will arrange transport for you to one of the expansions. I think your only option will be Kul Tiras, for the Battle for Azeroth expansion, for your first character, but you might be able to choose another. Even if you can, though, Battle for Azeroth is a fine expansion for a new hunter.
If you want to play through the quests from previous expansion, my advice is:
MAKE A NEW CHARACTER FOR EACH EXPANSION!!
When your hunter gets to 60 in Kul Tiras, turn around and make a new character, level it to 10 in its home zone, do some more zones in Eastern Kingdons / Kalimdor, and then go back to Chromie and choose a different expansion.
At the end of the process, you will have covered all the expansions, and you will have a strong warband of characters to choose from going into Dragonflight. Different classes and specialisations play very differently, so there will be a lot of variety in your experience.
You CAN stop your experience gain. I do not recommend it in your case though - you are already too high to enjoy Eastern Kingdoms, so best to head off to new lands, where you will meet challengers worthy of you. There is a character in Stormwind Keep named Behsten https://www.wowhead.com/npc=35365/behsten stealthed behind the table in the room on your right as you encounter the throne. He will stop you from gaining experience - for a modest fee, of course. But that isn’t what you want right now.
Please post again if you have any more questions!