- Tap on "Play Store" app (it looks like a shopping bag)
- Tap on the three lines in the upper left corner
- Tap on "My Apps"
- Tap on "Update All"
- You may be asked to reconfirm permissions on several apps, tap to give the permissions
You will have to give your phone some time to download the updates. After everything is downloaded (this happens automatically), you're good to go!
You may want to make it a habit to update your phone every week or every month.