You'll need to check your phone and see if your camera has a GPS locator that you can turn on. Most cameras don't normally have this. You can check in the setting of your phone by bringing up the camera. Check if it allows you to turn on the GPS. If not, you're going to need to download an app that will do this for you.
Normally all really good photos apps that are free won't allow you to do this. Therefore, you will need to purchase the app that can do this for you. I know of two different apps that will GPS tag your photos for you. They are Lightroom and GPicSync. In order to do this correctly, you'll need to make sure your phone is set to the correct time in your location and your camera will also have to be set to the correct time.