Nice job.  Suggestion: next time you do a video like this, instead of using the letter names (D, A, Bm, G) try numbering them (in the key of D, the same chords would be I, V, VIm, IV).  Going by numbers is good form for comprehending, memorizing, communicating and especially, transposing music.  If I'd know about it when I was your age, I'd have been so much better off...