Kirk was not a white nationalist, even though there is overlap in their taking points. The key difference is that white nationalist sources often present a more systematised ideology, often with explicit references to racial superiority, or calls for formal racial separation. Kirk did not publicly as far as sources show explicitly promote white supremacist violence or call for a white ethnostate.
As for burning in hell, thats just silly. There is no hell. No hot place where you go to pay for your sins. There is only the absence of existence. Charlie Kirk is just gone. Nothing of him remains anywhere.