Spontaneous generation was a (refuted) theory that some forms of life can arise from inorganic matter.
Louis Pasteur refuted it in a series of experiments, in which he boiled different matter (grape juice, broth) which would kill all the bacteria and let it stay for a long time to see if it would develop life (he also had a control condition in which he let the boiled liquid interact with the outside words, and those would develop bacterial life).
Hypothesis is what you think will happen before the experiment, it isn't necessarily backed up by any sources or evidence. A scientific law is the observation of a phenomenon and a theory is the explanation both can be used together to back each other up.