Gouache is a water-based medium, so you can water down to react and move around like watercolour. Blooms can be used to add in a base of colour you can then paint on top of. I load my brush with lots of water and a little pigment then I apply it to the paper.

Is gouache good for beginners?

Both gouache and watercolour are known as great beginner mediums. So when you are starting with painting you might have been introduced to both.

Can gouache be used after it dries?

One of the most wonderful (read: very practical) things about gouache is that even once your paint dries in your palette, you can reactivate it again with a drop or two of water. (In fact, you can even reactivate an entire dried out tube with some glycerin and water.)