In short: you can use AI, but you should use it tastefully.
What does that mean? Well, any good video starts with the script, which in turn starts with the research. Once you know what you want to say, and the vibe, you can generate the script and the music. And then the visuals follow.
During this process, AI /can/ be helpful. However, your final visual output should /not/ be AI slop. In particular, if you're doing 100% AI or anywhere near that, you're doing it wrong. You also shouldn't use the output of AI text generators verbatim, because if your screenplay sounds like ChatGPT, it won't sound good.
With that said, here are some AI tools you may find helpful:
And here some non-AI tools you'll find helpful:
Try Capcut in particular on desktop and mobile, as it's free and highly optimized for the 59s vertical video use case.
If you end up posting your video to your personal social media, please link back to this ns.com task page to tell your followers that this was an entry for an Earn competition. This will help you, because your followers may upvote your submission. And it will help your followers, because they can submit entries of their own.