To play triads, you would need only your 1, 3 and 5 fingers. Forget about the 2 and 4 fingers for now:
On the left hand:
5 3 1
C E G
D M S
On the right hand
1 3 5
C E G
D M S
Keep at it, and get used to it because this is the standard for playing triads.
Lesson 1: Introduction to the Piano
Lesson 2: Brief Introduction to music
Lesson 3: Keys of the Piano
Lesson 4: Singing and playing on different keys
Lesson 5: Intervals
Lesson 6: Chromatic Scale
Lesson 7: Circle of Fifths and Fourths
Lesson 8: Key Signature
Lesson 10: Fingering for the chromatic scale
Lesson 11: Introduction to Chords
Lesson 13: Chord inversions