very difficult to tell over the internet.
press the vol up plus power button until the phone restarts on its own. keep wifi turned off for this.
if you have a case and/or screen protector on, they could be causing an issue.
has the phone been dropped?
is fastboot ticked? if it is, disable.
if you installed or uninstalled an app prior to this, try and remove those recently added apps one by one and test to see if the phone returns to normal.
if the phone does not behave, you may have to do a factory reset.