hard reset it, backup your data first because you will loose everything.
To perform an hard reset you need to press volume up (bixby button too if you have one) and the press the power button while keeping to volume up pressed. You will boot into recovery mode and use the volume rockers to get to hard reset voice and then use the power button to confirm.
This will erase all your data, again perform a backup first. Then you may be asked your phone pin before accessing the configuration setup so remember that as well.
