The following is a list of materials that you'll need to start coding on an Arduino; these can be purchased from your favorite electrical hobby store or simply ordered online:
1 x Arduino-compatible board such as the UNO
1 x USB cable A to B 1 x HC—SR04 ultrasound sensor
1 x I2C LCD1602
10 x male to male wires
9V battery with 2.1 mm barrel jack connector (optional)
Laser pointer (optional)
Components such as the LCD panel and the ultrasonic sensor can be found in most electronic hobby stores. If they are unavailable in a store near you, you will find online stores that ship worldwide.