Well, I can't see what it's in now from your photo, it is a one gallon container? Yes almost surely it needs to be up-potted fairly soon, but it does look pretty healthy so it can probably wait a little while... really can't tell from the picture.
I would not fertilize it until it's repotted, and for myself I only use organic fertilizers, and generally use compost of some kind and don't fertilize per se. So someone else would have to advise you about that.
@RoseBlush1 might have some good tips for you if we can get her attention.
