First of all you get better by practicing, even if it’s just a few small doodles a day. Looking at references has really helped me, I recommend Pintrest for ideas, references, or just cool stuff in general. You can also watch videos. For blending I recommend using a blending stick and if you don’t have that you can use a tissue or something soft to blend
This is incorrect. Gouache painting is very very similar to watercolours, so much so that the two can be used together. It is an opaque method of painting.