when i set up a hard drive as a time machine, does it automatically delete all the previous data?

please help

i am kinda new to this whole time machine

and i dont remember being asked whether if i used the hard drive as time machine, all the data in the drive would be erased

i lost all my photos in the drive :(

is there any way i could recover the photos?

when i open my hard drive, theres just 1 folder named "backups.backupdb" and then another folder that has my macbook's name on it, and a file that says "2020-05-17-202450.inProgress" and i cant click on it.

says i need to download something from the appstore to open it / look it up on web

please help

thank you !!!