有 and 没有

규칙 有 = have: 我有一个朋友。
有 = there is: place + 有 + thing — 桌子上有一本书。
有 is ALWAYS negated with 没有 (or 没). 不有 is not a Chinese sentence.
Do not carry that over to 在, which takes 不: 他不在家。