I believe it is possible to view some options through char bazaar.
Select the filter "none" in vocations and the some available options will appear.
Hey, the island with trainers you mentioned is island of destiny, you go there after you get level 8-9 on rookgaard. At level 8 you can go to NPC oracle and she will teleport you there.
Here's where you find oracle: https://drive.google.com/file/d/1eNpeTFkfFQoU1I-Ahd7YBtp65P83pRum/view?usp=sharing
And before you buy a character, make sure you read the warnings, so you don't get scammed:
https://www.reddit.com/r/Rookgaard/comments/iisqnv/read_this_before_you_buy_a_character_in_char/
Also, if you teleport from rookgaard to island of destiny, you won't be able to return to rookgaard, unless you kill your character to level 5.
It's best for you to read tips for rookstayers:
https://www.reddit.com/r/rookgaard/wiki/index/rooktips
Endless Snow already told you how to find no vocation characters in bazaar.
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