Many YouTubers find that they sound more natural and engaging when speaking from an outline, rather than when reading from a full script. If you’re covering a complicated or technical topic, though, you might prefer to read word-for-word (or close to it) from a script.
This one is really up to you—so it’s a good idea to experiment and see what feels like the most natural fit for you. If you’re ending up doing an awful lot of video editing to correct missteps, you might find it easier to work from a full script.