The truth is,if you know how to play ukulele already,there's two ways to go about the chords. One is to use the upper 4 strings and play pure uke chords. I did this as when my Yamaha G1 arrived (it was used) it was missing the bottom string. So,I played uke chords on it for a week while I waited for the guitalele string set to arrive.
Then once the new strings were on,even tho guitar is my 1st instrument,I was at somewhat of a loss. I did look into buying a chord book for guitalele,which I recommend heartily to those who have never played guitar.
Now the guitalele tuned open is the same as having a guitar capoed at the 5th fret. While this kinda helped a bit,I was still somewhat lost,till I looked at a free guitalele chord sheet online. I looked at what on guitar would be an open G chord,and noted it was labeled as being a C chord. Then I looked at an open D chord,and noticed it was a G,which makes sense,as of course,that is a G chord on uke,and the upper 4 strings of the guitalele is C G E A. So then the light went on in my head. The name of the chord on guitar was 4 notes away from what it is on guitalele.
For example: the G chord form on guitar. I counted up 4 letters of the musical alphabet.. G,A,B,C. Landed on C,and C is the chord using that form on the guitalele. With the guitar basic D chord form,I counted up 4 letters again. D,E,F,G. Spot on. G is the proper name of the chord using that formation on this ukulele hybrid instrument.
So,I hope this helps those of you who are taking up guitalele.