Efficiently reading greens is a skill that is generally learned and earned through trial, error, and experience.
The Olde School method of going out, playing a lot of rounds, keeping your eyes open, ( watching all of your shots as well as other players’ shots carefully around the green ),is still the best way to gain valuable insight to reading greens. Learning to chip and putt well on your own is a large part of the beauty and satisfaction of the game! Although slow and tedious, the process is still the best way to become a great chipper and putter and earn confidence and skill around the greens.
Some keys to developing this skill are 1 . know that in general most greens will slope from back to front (down hill) 2. watch your previous shot and observe how it breaks #3 start looking at the putt from far out as you approach the green, and 4. look at it from below the hole when you get a chance. #5 have fun and enjoy the game as you gain experience!