What kind of YouTube chanel should I make?

I have a book review channel, although I have gotten WAY behind on this. I also have (gad) one devdoted to educating peole abiut methadone but the guy who was supposed to help me deleted all the videos. I do not have any thing beyond a camera on my computer, my phone and my KIndke Fire 8. I do not want yo invest until I have some sucess. My friend makes videos for a living (along with other art realted thngs) so she is willing to help me What subjects will get views? What subject is needed? One could be fun. I coild make more than 1 channel Ideas?