In the key of Cb major all of the notes in the scale are flatted. It is shown below.
In the next picture, the diatonic chords in Cb Major are shown.
Below, the chords are shown with guitar diagrams added. Most of the keys that have a high prevalence of barred chords will seem difficult for a beginner level guitarist. Spend time working on “E” type and “A” type chords and you’ll have most of the tools needed for successfully playing through all of the major keys.