出 (verb) = out; walk from inside to outside, as opposed to '進' or '入' (enter). 出门 (verb) = out; go out of the door; leave home. 外边 (noun or preposition) = outside. 出事 (usually used as predicate or attribute; 出 means happen, 事 means something) = something seems to have happened; something had happened; something was wrong; meet with an accident or mishap.

出 means to be out of or beyond something, or break down a stability of one situation. It is often used as a verb. 出门 literally means go out of the door, but actually spreads to refer to leave home. 外边 means outside. 出事 means something bad happened and it was beyond your expectation.