They say "experience is the best teacher", I can say that again because that is true. I remember when I forgot my pattern of my android device, I had to learn on my own how to help myself out of that condition. I'll share with you two methods of how to reset your phone. One the easy way, the other the hard way.
If you forgot your password or swipe pattern, android have built-in a way to bypass the lock screen if you have right to google credentials, in other words; if you have a google account. And this can be done without causing harm to your files, apps and all, that is why I call it the EASY way. The other is the hard way because you get to lose your files and all, it will be resetting the phone to default.
NOTE: That is way it is best for anyone to sync their google account on their android. It helps.
Method 1: signing in your google account.
Try the pin or pattern five times. In order to bypass the password lock, you will need to attempt it five times or more, your phone will lock again, but you'd be given option to login using an alternative method. (Your Data must be on) you can toggle it on by pressing the power button.
Tap "Forgot password" or "Forgot Pattern" this button will bring up the google account login screen as shown above, allowing you to login by providing the google account credentials for the account associated with the phone.
Once you're logged in, set a new lock screen password so you can safely lock and access your device again. You can do this by tapping the settings apps 》 selecting security 》 you can choose whether to lock with a pin, pattern or password.
Method 2: resetting the phone.
Turn the phone off. In order to access the recovery mode, you will need to start with a powered down phone. Press and hold the power button along with the volume down button, this must be pressed together.
NOTE: resetting your phone will erase all the data on it, so it should be used as a last option method. If the phone is frozen, you can remove the battery.
Press and hold the volume down and the power button, once the android image appears. You can release it. In other cases, you will need to reset it manually by using the volume buttons to reset it.