Can not Masking

 I have been trying to use the mask option, and I can not use it at all. I have been watching lots of YouTube tutorials about masking, I have been  following them step by step and Nada. 

I put a video on time line,  then I put the second video on the other time line, I go to effect contol - opacity- got the pen, drew points around the object and nothing happen. I can not see the video under the masking, when I press play I just see the video on the second time line, I cant never see the video on the first time line. 

This part has been very frustrating, cus I have been able to do preatty much all with the YouTube help, but this masking effect doesnt work for me at all, maybe I need to re downoald the program. 

Any sugestion I will apreciate it, I have been stuck for a week trying to find the soution to this.