First of all - good luck. Exciting times ahead.
It is actually surprising how many 'bad' explanatory videos there are out there, so the fact that you are seeking advice shows that you are already one step ahead of the rest.
Here are the key factors that you need to take into account when creating your video:
1. ask your target client's what is their main 'pain' or their main need. Once you know this, then that is the issue that you need to emphasize in your video.
2. Who are your target customers. If they are businesses that already know your competitors or work with them, then you might want to briefly mention why your product is better (for the customer) than your competitors. That said, spending valuable minutes on comparing your product to other products is usually time wasted.
3. Don't make the video longer than about 90 seconds.
4. It has to be super clear regarding the following points: what is the product/service / what it does, why it helps solve the need/problem and a call to action at the end.
5. Needless to say, it has to be of good quality from a visual point of view. Colors, images and types of people that appear in the video affect the engagement with users.

I'm not sure what your budget is, but you can get decent videos for decent prices on Fiverr - so if your budget is sufficient, you may even be able to create 2-3 videos and then test which gets the best results.

I've successfully helped over 300 entrepreneurs and I'd be happy to help you. I can review your script and planned video layout and then give you my thoughts and advice during our call.
Good luck