When I was your age I caught birds with a simple wooden box. Prop it up with a stick and place food under the box. It's best to place it so that you can see it from a window. Leave it and refill the food daily. After a few hours you'll see sparrows come to eat. Shyer birds like blue jays take several days, but they will also eventually show up.
When you have found out when which bird comes, simply tie a rope to the wooden stick. Leave your window cracked just enough to have clear way for the rope. When the desired bird is underneath the box: PULL.
Make sure to comply with local, state and federal regulations, and please don't harm the birds. Catch & release is fun