Why can't I paint ?

Hi, so I've been doing my lineart, and as I createda new layer to paint, it doesn't work. Like I selected the brush, it is on normal mode, none of my layers are locked or whatever and still can't paint. I'm a newbie but I really don't know where the problem is

Hi, so I've been doing my lineart, and as I createda new layer to paint, it doesn't work. Like I selected the brush, it is on normal mode, none of my layers are locked or whatever and still can't paint. I'm a newbie but I really don't know where the problem is