Adding more than one note, of different durations, at a time.

Hi everyone, and apologies in advance for a fairly basic topic. I've done this before but I can't remember how, and I can't find the info in the musescore handbook.

What I want to do:
You know when you are playing the piano, you can play more than one note a time, anything up to 5 notes per stave. And sometimes you hold one note for the measure but the other notes change? How do you enter this into musescore? I can add a second (or more) note of the same duration by going back to the original note, pressing shift, and then the letter of the note I want to enter, but the notes have to be of the same duration. I can get around this by breaking the longest note down into smaller notes and using a tie to make it sound like a longer note, but that is tedious and not the way it should be written.

Anyone know how to do this, or what it is called in the musescore handbook?

Thanks!