Plan B at 16

Im 16 and my boyfriend and i wanna try going unprotected. i feel safe with him and know we’re both clean so i feel completely comfortable going without a condom just atleast once. i just know id need plan b but im worried about how and where im supposed to ask for that? do i just find it at my local walgreens and check it out or do i have to ask for it and get id checked or something? also what about birth control..? my parents cant know any of this