[25M] [25F] She works at the store that I go weekly.

So I've started taking this new course as a hobby. And there this girl at the front desk. It' nearly been 2-3 months since I've started the course. I've been trying to talk with her and I usually do. But these are small talks and not often personal or long conversations. I'm really into this girl and I feel attracted towards her. I've had a chance to invite her out once but she said no thanks. I want to keep trying but I am way too tired and feeling overwhelmed. Does anyone have suggestions on what could be done ?

Thanks in advance y'all. Big luv <3 <3 <3