not to sure about rebooting please help.

So I had my phone repaired awhile ago at a little phone store and I went back into the store at the start of this week due to my phone being unresponsive and a black screen. automatically it started working soon as I got there and the lady then done a hard reset maybe.

Now this morning, I was able to get into my Iphone 5s numerous times but now the touch screen has frozen on me. the home button and power button still works same with siri, I recall the lady saying something about a hard reset? I'm sure that's what she done but I'm not a hundred percent sure and I'm afraid to attempt it as my phone isn't backed up and I don't want to loose anything such as photos/videos/, texts, etc.

so yeah if anyone could help with that information weather it keeps all files would be very much appreciated! Thanks heaps 🙂

ps. my phone has the recent IOS update.