In order to form a negation in Past Simple you can also use an auxiliary verb (was, were) or a modal verb (could). In that case the negation is formed with „not. For example: I wasn't/was not at the football match yesterday.
To form a question put was, were or could at the beginning of the sentence. For example: Were you at home last night?
Be careful: Use „were/weren't“ for you, we, they