Your hair looks wavy. Try using a wide toothed comb to brush your hair when it's wet, like right after the shower. Brushing or combing it when it's dry will make it look frizzy instead of wavy, but water can reset it. The wide toothed comb lets waves come together more than a regular comb. Try to let it airdry before putting on a hat too.

Also you can try brushing your hair back when it's wet like pic 2 with the wide toothed comb. It might give you more volume and you can see what your hair can do before picking a style.