With regard to the tangibility of chords different instruments are preferred to special keys, for a beginner on the ukulele the simplest chords, depending on the tuning, are to play in the key of C major and A minor (C-Tuning), or in the key of D major and B minor (D-Tuning). In principle, all keys can be played - with a little practice.
D-Tuning (traditional standard, still in Canada and Europe)
The point of view is as shown by the picture in the left. Numerals denote the following fingers: 1=indexfinger, 2=middlefinger, 3=ringfinger. My fingersettings may differ from most chord tables, but they are more practicable for any changing to other chords. With these few chords you are able to accompany a lot of tunes - many simple songs actually need only two chords!
All keys, both, in C- and D-Tuning gathered in my so called Ukulele Circle This is
a key circle, also known as circle of quints (circle of fifths), showing 11 chords in each key. It is helpfully
for understanding harmonic structures, and for transposing the key of a song.