New to Instantpot -- and TERRIFIED of it

Hello all! I am new to Instantpot, and my mom gifted me one as an early Christmas present. She lives across the country, or else I would be grilling her with questions-- So I have ended up here!

I've heard about natural release and instant release. If I don't press instant release, will all of the pressure dissipate on its own? Like, can I go to the grocery store while it cooks without fear of it exploding? I am currently using it, and I am too scared to leave the kitchen. (My chemistry teacher in high school instilled this fear in me).