It may be worthwhile to look to get help from WOW TBC Gold an outside source. Having someone you know are accountable to you and also be there when you need to talk to someone. This could be vital in staying away from issues you're not equipped to handle.
TBC is the default setting for the vast majority of players since there is no new content in vanilla.
Some characters remained vanilla, which is why you can choose however I wouldn't recommend it as the populations are less than scarce and you cannot change your character's name to TBC. They're also releasing Season of Mastery, which is mostly vanilla and cheap WOW Classic TBC Gold will be replacing the classic era servers.