Possible UTI?

Patient: Hi, I’m female and 14. In the last few days it really really burns when I pee. It hurts so much that I have to stop. I feel like I need to pee all the time and my lower stomach hurts so much, and is worse when I wear tight clothing or have something resting on my stomach. I’d rather not tell dad, is there something I can get from the chemist to help?