I need some major hair tips! Wavy, curly, volumnizing techniques/sprays?

So i have very short, straight hair. Id like to have really cute summery waves some days, is there a spray or a technique i can do to achieve this? Thanks so much! Also, the same question goes for curly, can i get curly hair with a spray or something too? Id just like to have some natural volume without an iron or something. Oh, and any tips for volumizing my hair? I have very fine hair. Thanks so much!