Finder

Get to know basic: side bar, application menu, views, file types

Get to know useful: Search, Finder preferences

Organise files: New Folder, rename and delete files

Move files with two windows: Drag and drop. Open two Finder windows then select and drag files from one window to the other

Move files in same window: Drag and drop files in same Finder window in Column or List View. Select then drag a file over a folder in the same window to move it there

Move files to folder pinned to sidebar: Select then drag a useful folder to the sidebar then drag and drop files into that folder