This is a video going over the main ways of entering MIDI notes in Studio One 6. The methods can carry over to other versions of Studio One or different DAWs, but the specific keyboard shortcuts, UI, etc. are unique to S16. I definitely recommend checking out the program if you aren't familiar with it.
In this video I talk about entering MIDI data manually, and with a keyboard. I also bring up entering a previously made MIDI file, but that is pretty simple. I realized part way through recording that OBS wasn't ready to get sounds from my DAW so the Synth sounds aren't great, but since we won't worry about the quality of the synth sounds until the next video, I'm not worried about that.