coworker likes me

i need advice, for a heads up i’m 18f, and he’s 20m and i have a coworker who confessed that he’s into me. in the heat of the moment i was like “i could give it a shot” but a few hours later i’ve decided i really don’t want to. i know everyone might say “some things work out, some things don’t,” or “it’s okay if it doesn’t work out” but i don’t want to even TEST if it does. my life is too busy for relationships, and i’m focusing on college too on top of everything. what can i do? please help me guys 😭. maybe easy rejection tips, or how can i show disinterest? thank you in advance, sistas 🫶🏾