If I sell character will my DK be deleted

I have Paladin and Death Knight and I want to sell paladin . Do I need to lvlup another char to lvl 55 so my DK wont be deleted

As a Premium member you can make a dk without requiring a lvl 55toon iirc ( if that perk still exists)

but regardless your dk toon will not be deleted. I have an account with just 1dk