A couple of things come to my mind. First your frame range in the output properties, maybe you have the wrong range set or the steps. If you restrain the rage in your timeline to say just frame 10 and you do a normal render, does that render come out black and with little kilobytes? Maybe you’re rendering with a strip on the video sequencer editor? There could be so much to troubleshoot since is a render time problem. Maybe you could upload your file for us to take a look.
