The Arduino IDE provides a sample sketch with a simple program outline in a text window when you first open it. There are also a vast array of code samples under the File->Examples submenu item.

If your Arduino has a built-in WiFi or Bluetooth chip, such as ESP8266, it may have a separate LED that starts blinking as soon as you plug in the Arduino. Some Arduinos have two onboard power LEDs.

In Arduino IDE 2, you will need to click on the Library icon on the left pane, and this directly takes you to the Library Manager page, which lets you search for libraries or browse through a list ...

The Arduino Zero, which is already integrated with a built-in debugger, can be used with the Arduino IDE 2 Debugger without any extra hardware.