Masturbation Questions

I’m pretty new to masturbating since I’m almost 14, I’ve started to masturbate in my bath with an electric tooth brush and I do have a few questions. First one is how do I get off from laying down? I can only get off by putting my chin on the side of the bath and placing the brush on my clit I can’t get off by laying down at all. Another question is how can I get a better vibe that my parents won’t find out about (I’m an only child so they are protective but they are not against masturbating since they are pretty chill) and my last question is that is it normal for penetration to not feel good I have tried inserting fingers before but it either feels uncomfortable or there is no good sensation. Thank you for reading and plz answer if you can!