Storytime- Beginners luck

So recently I've decided to take on painting, because it's an expensive hobby, I got a child's waterpaint kit to start off with as well as a few canvases that I could wash and repaint (for practice purposes.

So last week Friday, I got the stuff and as soon as I got home I started painting... It looked wonderful and unfortunately a picture of the painting didn't do it justice.

I was so proud of my first painting ever, but I wasn't fully happy with it so I washed the canvas to retry later, once the canvas was dry.

Skip to a few days later... The canvas is finally dry and I get all of my art supplies ready to try again.... This time it didn't work, I'm not sure it it's because I needed to prime the canvas first or if I only had Beginners luck, all I know is that the second time I tried painting, it looked like a two year old got hold of the brush, in fact, a two year old would have probably done a better job.

So I have a question for all the artsy people out there, do I need to prime my canvas before painting, what works best for this kind of water paint and what kind of brushes would you recommend (mine are shedding)?

Xoxo
@thegoldencookie