The complement to major
A minor chord is the same as a major chord with a downward adjustment of the middle note. This is called “lowering the 3rd”. Start with a perfect 5th, with either hand, then fill in a note in the middle but closer to the bottom key than the top. E.g: C Eb G, F# A C#.
Get comfortable with this chord, then copy it to the other hand. Now play the chord with both hands. When you can do 12 of them, each with a different key on the bottom, you have root position major chords in their simplest form, also closed.