The tools

ToolShortcutIntroduction
SelectVSelect, move and transform elements on the canvas. Values will be snapped on the X axis to the unit set in the Snap X field on the bottom right. When in select mode, you can also tick the “Use as input” checkbox in the bottom instrument panel to use the on-screen keyboard to input notes with selected durations. You can also right click on various types of elements to see some commands available to them.
QuillQ

Draw notes onto the canvas. If there aren’t enough bars to contain the contents on the canvas, new bars will automatically be added unless you turn off automatic bar management in the Composition Panel.

Value set in the Snap X field is also applied to the Quill tool.

KeyframeK

Draw keyframes onto the canvas.

Value set in the Snap X field is also applied to the Keyframe tool.

RecordRA basic recording feature that records real-time MIDI or on-screen keyboard inputs.
TextTDrag on the canvas to insert markdown-based text boxes for adding notes to your compositions. They will not show up in play mode. Read more about the text nodes.