I believe what he's saying is he's going to level the druid from 1 and if at some point he says "fuck it" and hates the class he's going to yolo swag boost his warlock to 90 to forget the pain.Do you got boa's? If not and you dont really have any significant stuff on your original account you ought to highly consider just making a new account and getting RaF'd for the 300% exp boost so you can level super fast if you're wanting to get up to end game stuff and garrisons. Just make sure you RaF with someone with the time to match to play with you etc. If you look on mmo-champs forums too there are lots that will actually pay you in gold and other things to RaF you because they want mounts n the like.
Or I know you're saying from level 1 but if you got the draenor expansion on your current account, you should have the ability to boost one toon automatically to 90 for free so you could also consider that, though if you've never played a druid before(or most anything) it might be a steep learning curve from there hehe.
Anyway just thought I'd throw that out to ya.
You don't really even need to RAF unless you want to be at max level within a day or two. For someone who hasn't played in a long time, levelling through the content can be nice. And it's so easy to level now.