My guess is it's happened by now - but here is my 2 cents anyway! He probably knows it is the first time you've done this, so LOOK at it. Really explore it. Hold it in your hand, feel which way his erection pulls, look at the veins, then lick them, feel the tip with your tongue. Explore him. Run the tip across your lips and cheek. Kiss it. Don't worry so much about doing something TO him. Look at the places where it changes, thicker at the bottom, where the shaft meets the head, use your tongue and hands on those bits and check his reaction. Gradually you will learn that licking one spot will have a greater effect than another and you'll use it! Men have grown up with their cock, but to us it is all new, so get to know it - it has a mind of it's own most of the time anyway!