Can you get deficient in cholesterol if you are vegan? is there a disorder where the body cannot make enough cholesterol unless you ingest it?

No to both: This is something people may tell you about the dangers of a vegetarian diet, and it's actually not true, just an ill-informed conclusion from the fact that the diet itself contains no cholesterol. If and only if you supplement nutrients as required, bring a vegan is safe though the health benefits have been greatly exaggerated. Your physicisn is your best guide.