How do I put my last backup on my new phone

Hello Juanaue4,

Welcome to Apple Support Communities. We'd be happy to provide some guidance. If the previous owner haven't already, you'll need to erase the iPhone, and remove their personal information either use Settings, or by using a computer. Here's how:

Use Settings to erase iPhone

1- Go to Settings  > General > Transfer or Reset iPhone.

2- Erase all of your data from iPhone: Tap Erase All Content and Settings.

Use a computer to erase iPhone

You can use a Mac or Windows PC to erase all data and settings from your iPhone, restore iPhone to factory settings, and install the latest version of iOS.

1- Connect your iPhone to your computer with a USB or USB-C cable. You may also need an adapter. See Connect iPhone and your computer with a cable.

2- Turn on your iPhone.

3- Do one of the following:

• On a Mac (macOS 10.15 or later): Click the Finder icon in the Dock to open a Finder window, click the iPhone button in the Finder sidebar (below Locations), click General at the top of the window, then click Restore iPhone.

• On a Mac (macOS 10.14 or earlier) or a Windows PC: Make sure you have the latest version of iTunes (see the Apple Support article Update to the latest version of iTunes). Open iTunes, click the iPhone button near the top left of the iTunes window, click Summary, then click Restore iPhone.

Erase iPhone

After erasing the iPhone, you can restore your iCloud backup as follows:

Restore your device from an iCloud backup

1- Turn on your device. You should see a Hello screen. If you already set up your device, you need to erase all of its content before you can use these steps to restore from your backup.

2- Follow the onscreen setup steps until you reach the Apps & Data screen, then tap Restore from iCloud Backup. 

3- Sign in to iCloud with your Apple ID.

4- Choose a backup. Look at the date and size of each and pick the most relevant. After you choose a backup, the transfer starts. If a message says that a newer version of software is required, follow the onscreen steps to update. If you don't see onscreen steps to help you update, learn what to do.

5- When asked, sign in with your Apple ID to restore your apps and purchases. If you've purchased iTunes or App Store content using multiple Apple IDs, you'll be asked to sign in to each. If you can't remember your password, you can tap Skip this Step and sign in later. You won't be able to use the apps until you sign in with your Apple ID.

6- Stay connected to Wi-Fi and wait for a progress bar to appear and complete. Depending on the size of the backup and the network speed, the progress bar might need a few minutes to an hour to complete. If you disconnect from Wi-Fi too soon, the progress will pause until you reconnect.

7- Now you can finish setup and enjoy your device. Content like your apps, photos, music, and other information will continue to restore in the background for the next several hours or days, depending on the amount of information there is. Try to connect often to Wi-Fi and power to let the process complete.

Get help with restoring from your iCloud backup.

Restore your iPhone, iPad, or iPod touch from a backup

We hope this information is useful. Kind regards.