I am currently playing Minecraft Pocket Edition for Android and as a new player one of the early challenges I found in it is owning bow and arrows. Having a range type weapon gives you the advantage to take out targets from a safe distance especially for taking out those green monsters that explode upon contact. But crafting the arrows eats up a lot of resources and consume time. Luckily, there's an easy way to do this.
What you have to do is own a stone sword first then wait for night to come. Take out those skeleton archers and they will drop off some arrows. Or if you can't handle them with melee combat, just watch from a safe distance and wait for the sun to rise so that they will burn and they would still drop off arrows plus some bones.
If you must craft bow and arrows you must do a lot of mining but in survival mode monsters will just pop up behind you even if you are deep underground. To prevent this, go to options and turn down the difficulty. This way, there will be no zombies, skeletons or spiders spawning behind your back. Now that the coast is clear from enemies, go mine for flint. You can mine it from gravels. Use shovel to speed up the digging. After that, you will have to hunt for chickens for their feathers.
To craft the bow, you must slay some spiders and get strings from them. Check out my video showing how I
craft Bow and arrows in Minecraft Pocket Edition for Android.