i want to be safe from my child use my iPhone, what i have to do? To restrict my device running on iOS 10.2?
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 & Passcode.
Or you can use third part apps that block specific content and apps.
You can also use the learning mode to keep your child within a specific app, like a puzzle or game that you allow it to play.
Settings > General > Accesibility > Learning
Enable Guided access. Configure a passcode Optionally configure Time limits.
Now open the app your kid wants to use/play, triple-click the home button - select the area that may be clickable - select the hardware buttons that are allowed (volume is a good one :)) - click start.
You kid can now only use that specific app, without leaving it.
To exit this mode, just triple-click home and enter the configured passcode.
I use this all the time with my kids (also on iPad).