Listen I'm 13 and I masturbate I use my old hello kitty electric toothbrush as a vibrator but if use a toothbrush you should put like tape or something over it cuz it might be stained with toothpaste or something. Also when I was little like 6 my mom told me if I ever wanted to masturbate just tell her and she would give me privacy but I had no idea what she was talking about and I didn't even start until I was 8. Just know that your parents went through the same thing your going through and everybody's goal is to not get caught but sometimes if you have a sibling who does it to it might seem weird but maybe like every other day you could keep watch when your sibling does it and they could do the same for you.
I always masterbate when my parents aren't home or late at night like you if you want to watch porn while doing it but you don't want anyone to hear use ear buds or in the shower when no one is home use a speaker or if you have a water proof Bluetooth speaker like me you can have your phone hext to the shower peak out and connect your phone to the speaker and I agree with the rubbing your foreskin on the floor but you should also try using lotion in your hand it feels even better. Just to let you know
feel like I am flyinggg.....