Hi penny. You can factory reset the phone and just enter the same Google account. Unfortunately, doing this will mean deleting all the files you saved in the phone.
Follow this to factory reset the phone:
Switch off the phone.
Press and hold the Volume Up, Home and Power buttons.
When you see the Galaxy logo release only the Power button.
Use the Volume Up/Down buttons for navigation and the Power button for choice.
From the android system recovery menu select wipe data/factory reset -> Yes -- delete all user data -> reboot system now.