This is a fairly rare confusion, but it's still one that made it into a Kettering newspaper!
Sort is a noun; the kind of thing something is.
e.g. "the animal in the bushes was a sort of gibbon."
Sort can also be a verb.
e.g. "Will you sort out your desk?" asked John's wife.
Sought is the past tense of the verb "to seek". So, if you were looking for something, you had "sought" it.
e.g. "Tony Blair had sought a solution to the problem of nuclear waste for years."