Hi @Dave_111 Welcome to the Samsung community 
if you are using Samsung Messages any deleted texts are retained in the Recycle Bin for 30 days. Tap the Dot Menu Bar on the right of the Messaging app and select Recycle Bin. you can restore any available Messages from there. However it is advisable to back up Messages, are you backing up to Samsung Cloud. if you go to Settings,Samsung Cloud can restore any Back ups.
Currrently Samsung Cloud does not back up photos (though speculation that is set to change again). Do you have photos backed up a Cloud service or Local Storage? Have you searched in My Files as well as Google photos? Do you have syncronisation with One Drive set up? Are you photos not backed up anywhere else such as Dropbox or an External local storage Device? I would recommend backing up photos and files, cannot really take the chance.
Some information here https://www.techradar.com/best/best-ways-to-backup-photos
