I recommend that every new (or "new-ish" :-) user take an hour or two and simply read the entire Handbook (https://handbook.musescore.org/). Don't try to memorize it! Just skim through it and familiarize yourself with the contents! But read it all!!! Then you'll have an idea where to find things when issues come up in the future. "Didn't I see something about that in the Handbook?"
The parts you will be interested in for your specific question will be found in ...
Comments
Did you check the handbook on note entry?
Reading the handbook will save you so much time.
I recommend that every new (or "new-ish" :-) user take an hour or two and simply read the entire Handbook (https://handbook.musescore.org/). Don't try to memorize it! Just skim through it and familiarize yourself with the contents! But read it all!!! Then you'll have an idea where to find things when issues come up in the future. "Didn't I see something about that in the Handbook?"
The parts you will be interested in for your specific question will be found in ...
https://handbook.musescore.org/introduction/create-your-first-score
https://handbook.musescore.org/basics/entering-notes-and-rests
... but do read it all
Welcome aboard and best of luck!!!