The entry level activities in climbing are top roping and bouldering. Top roping is great for the ground that the climber is safe from risk of falling. This allows the climber to work on movement techniques while learning to trust the rope.
Find friends who know how to climb or are willing to learn with you. This is an important step because humans are sociable creatures. Climbing will be much more enjoyable if you can laugh and joke around with some friends.
Once you have been trained in how to top rope, shopping a rope and the equipment and start climbing on the anchors that you build.
Bouldering is another step for learning technique, building strength and getting out there without a partner.