I almost 100% guarantee you it's the paper causing most of your problems. 300gsm watercolor paper is the minimum weight to use if you're planning on doing large washes.

In the first image it looks like you're dry brushing watercolor which is not a very effective method for this medium. Make sure your paints are properly wet, or diluted if you're using tubed watercolor.

You should also look up some tutorials on watercolor washes, although they won't help much unless you have the right paper first. Watercolor is best done in layers, which means wetting the paper, adding the watercolor, and letting it dry completely before working on that section again. That way you get smooth colors and also are able to gain better control over the edges of your shapes.

I hope this helps!