anon626
There is seedvault in the system settings but I wouldn't trust it honestly.
You can download an app thatll backup various things to a file on your phone or a USB device.
Or export/backup things from individual apps with the functionality.
For example fossify messages is on the play store or fdroid.
https://github.com/FossifyOrg/Messages
Set that as your texting app then export your text messages. It should be 1 file I would guess.
It's recommended to get a new contacts app, calendar app, files app.
Fossify contacts can export your contacts into 1 file to later import if need be.
I don't know if you have cloud storage or what but I guess upload the exported files there or to a PC or USB drive. Good idea to have backups in 2 places in case your pc dies or lost or There's a flood/fire.
It's a good idea to backup before going to the phone repair store. Anything could happen.
I think you're getting close to the end of the tunnel and it'll all work out <3