Hi,
If you've got a recent back up stored in the Samsung Cloud then install that. If you were backing up your contacts and passwords to Google, then just add your Google account to the phone and these should become available immediately.
Or head to settings> general management >passwords, passkey, and autofill. Choose your preferred service.
For notifications follow this
Settings>Notifications >Advanced settings >Manage notification catagories for each app. Toggle that ON.
Then goto
Settings>Notifications >App notifications. Tap on each and all of the apps you want to assign sounds to. Tap 'Notification catagories' and toggle on each catagory as appropriate.
To assign a sound to each catagory then just tap on each one and tap 'Sound'. Choose a sound.