Just as major and minor triads are more common than augmented or diminished triads, some types of seventh chords are more common than others. The most common is the dominant 7th chord, which you have already learned. After these, the next most common types are major 7ths and minor 7ths. Some useful major 7th chord shapes are shown in the following chord diagrams. Learn them and then play the following example. Once you can play it comfortably, practice the chords as arpeggios, as well as experimenting with substituting them for major chords and making up your own progressions with them.
Amaj7
Bmaj7
Cmaj7
Dmaj7
Emaj7
Fmaj7
x Gmaj7