How to Set, Use iOS 10.2 Parental Controls on iPhone 7 Plus
What exactly do you want to restrict?

You can restrict apps:

Settings > General > Restrictions > Select app.

You can restrict websites, content:

Settings > General > Restrictions > Allowed content.

You can set a Password:

Settings > Touch ID &amp; Passcode.

Or you can use third part apps that block specific content and apps.