How do I adjust the sound

The iPad User Guide is a rich source of information about your iPad. Here is a direct link to the relevant section of the Guide:

Adjust the volume on iPad - Apple Support

As you’ll see, you can adjust the audio volume in several different ways…

1) the physical buttons on the edge of the iPad…

2) using the Control Centre, with a downward swipe from the top-right corner of the screen - then drag 

3) or, for system sounds, dragging the slider in iPad settings:

Settings > Sounds > [Ringtone and Alerts Volume]

Hi! You can adjust your iPad’s volume by pressing the volume buttons on the side. Alternatively, you can control the volume through the Control Centre: Access Control Center on your iPad - Apple Support

Take care!