Contemplative prayer is when you sit quietly and try to connect with God or your inner self. It's kind of like when you take a deep breath and let all your thoughts and feelings settle down, so you can feel peaceful and calm.
You might sit in a comfy chair or on a cushion on the floor, and close your eyes or focus on a candle or a picture or something else that helps you feel centered. Then you just sit there and try to be quiet and still and present in the moment. You might repeat a word or phrase over and over to help you keep your mind from wandering too much.
It's a bit like when you're playing a video game and you need to take a break and pause it for a while so you can rest and recharge and be ready to play again later. Except in contemplative prayer, you're taking a break from your everyday life and worries and trying to connect with a higher power or your own inner wisdom.
Some people find that it helps them feel more connected to God or to themselves, and that it brings them peace and clarity. It can be a bit tricky at first, but like anything else, it gets easier with practice.