That’s the typical setup.
Here’s what to do:
OpenSettings.
One way to get there is to swipe down from the top of the screen, then select thesettings/gearicon.

Go toSounds and vibration>Ringtone.
Choose the sound you want as your ringtone.
This means you could set individual tones for each contact.

Here’s how to do it:
Open theContactsapp.
Choose a contact you wish to give a custom ringtone.
Select theEditoption (pencil icon).

TapView moreto expand the page to include more parameters.
Scroll down and tapRingtone, and then pick a new sound.
SelectSounds and vibrationfrom the controls menu.

Tap theNotifications soundoption to select from a list of available tones.
Choose the tone or song you want and youre done.
To use a different sound, ensure it’s stored locally in one of your phone’sNotificationsfolders.

you’re able to copy sounds to the right folder with the My Files app.
Scroll down and selectApps.
Find the app you wish to customize in the list and select it.
On the app info page, scroll down and chooseNotifications.
SelectNotification categories, then tap on the pop in of notification you want to change.
SelectSoundand then choose the sound you wish to use.
FAQ
From the Phone app, select thethree dots icon>tweaks>Voicemail>Notifications.
Open your phone’sSettingsand selectNotifications>See All> thethree dots icon>Show System Apps.
Next, pop kick open the drop-down menu and selectAll>Samsung Account, then turn off notifications.