There is no time like the present to get started on Spring cleaning, and I recommend starting with your phone.
First thing to do, backup your device to a computer or preferred cloud based management system.
Next, swipe through each page of your phone, if you see an app that you've not used in along time delete it. The app will still be available to you via your backup or downloads (via iCloud, App Store, or Google Play)
Next get those photos backed up.
My preferred method is using the Goolge Photos app.
A free app with unlimited free storage.
Download it, log in with your personal google account and walk through the setup steps.
Once it's all setup it'll run in the background. (For iOS users, you'll need to open the app and let it run while it backs up your photos. I recommend plugging your phone in to a charger so that your battery does not die in the middle of the backup. The assistant tool will tel you when your done)