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This depends on how you will use it. Writing a script will help you focus the content to essential points, avoiding rambling and making videos shorter. A script can also help with editing captions or be used as a transcript (some students prefer reading to watching). However, it is better not to read off a script as it diverts eye contact away from the vieweviewer, producing a flat and lifeless delivery.
Having written a script will allow you to create prompt notes that you can dot around your screen that will help you remember the essential points you need to make.
Using prompt notes rather than a detailed script will produce a more natural and engaging delivery.
If you stumble or make a mistake, it is better to carry on and correct yourself as you would in person. If, at the end, you feel unhappy with the delivery, you can always do another take (link to doing a number of takes).
For convenient editing, when you stumble and want to continue on the same take but do it again, you can put an audio/visual marker in, like clapping your hands, so you can quickly jump to where you need to make cuts.
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When you are happy with your content you can share it with students through your Moodle course.