A lot of youtubers start off with low grade equipment, so I think your phone should be fine for now. It's not going to sound perfect, but it won't sound terrible.
There are phones that are excellent at recording. There are few friends that are starting out in music (they formed a band) and since they are not that equipped, their phones come in handy and they aren't of poor quality by the way.
Which phone? The biggest problem for me now is the placement. Due to the size and range of the screen, I'm limited in terms of possibly recorded distance and sound. It also tends to be unsteady.