As an intermediate guitar player you should know all the concepts of the beginner, and also the following concepts as well.
Tuning Your Guitar
Be able to tune using all of the following ways:
Relative to Itself – 5th fret technique
Tuner – tuning app, or one you buy in the store or online that sits by your guitar or clips on.
Learn how to change your strings
Be able to read tablature fluently recognizing chords easily when seen on a tab sheet.
You should have a repertoire of at least 17 songs.