Blank screen with mouse arrow only!

I tried logging on with finger and it stated it wasn’t registered. The. I tried password and I guess I didn’t use the right one. The. I did the code option and I thought I entered the code correctly but am unsure. Not I have a blank screen with only the mouse showing. I just bought this laptop!  I tried powering on and off several times. I tried the F12 and the F8 options I read on here. Nothing is working!  How do I log on to my computer??