You will need to back up your settings to iCloud.
On your phone so to Settings, choose your user ID, click on iCloud, and choose what you want to save. Bookmarks, Calendar, Contacts, etc. You can select photos and choose to save them to iCould. If you have a lot of photos, you may need to purchase additional storage from iCloud.
If you buy a new phone my suggestion is to get it from the Apple Store. They ask you if you need help and can help you migrate all your stuff to the new phone and show you how to do it for future reference.