like you do believe but you either a. don't see/feel magick in your daily life or b. can't shut off that logical part of your brain saying things that makes you doubt magick? either case, i would say reading and practice would help you.
i don't know your path so i don't want to recommend books for Wicca when you're into straight up magick without any spiritual elements. try to learn about magick, what it can and can't do along with how it can manifest. magick is natural energy, it works in subtleties most people might miss. an example would be you cast a love spell to find someone [no one specifically you know] two weeks pass and still nothing. later that week you're walking home from school the same way you always go, when you suddenly feel the urge to walk down a side street. taking that side street you bump into someone. the two of you start talking, hit it off and after a few weeks/months you start dating. that's how magick typically works. you won't throw a rose into a bubbling cauldron, a cloud of smoke bellows up, and poof the person appears, it takes time and effort to work.
for practice, try meditating, energy work, and balancing your chakras. this can help you focus, feel and control the energy, and help it flow through your body without pooling and making you feel sick. walks in the woods or somewhere near nature, alone, without music, i find is a good thing to do. just observe everything, try and connect with the world around you. you might start to feel the energy flow around you. [if you are also practicing magick for a spiritual reason, i feel it helps connect with the divine when you're in nature]
don't stress, or try to hard. i went through the motions when i started, for the first couple years i was confident, then i began to doubt. you will find a happy place eventually where you discover the truth for yourself. blessed be.