Hello j_curt,
Welcome to Apple Support Communities, and to the iPhone family! We are excited to have you join us! It looks like you're having a question about adjusting volume on your iPhone, and we'd be happy to provide some guidance.
In order to adjust the ringer volume and not the volume for things like music and videos, you can go to: Settings > Sounds & Haptics. Here, you'll see a slider for 'Ringer and Alerts'. Go ahead and adjust this slider to where you'd like it.
Make sure "Change with Buttons" is turned off so your ringer, and alert volume won't change when you use the volume button to adjust volume for media and music.
For more information, please check out these helpful links:
Adjust the volume on iPhone
Change iPhone sounds and vibrations
We hope this information is useful. Kind regards.