Would I be safe? What would my chances be?

Im planning on having sex for the first time ever. I’ve always been sooo afraid of pregnancy so I want to make sure what I plan on doing is 100% safe and responsible.

Would I be safe if I were to have sex with bc that is 91% effective, used spermicide and had him wear a condom? Sorry if it sounds crazy but the thought of triple protection kinda eases my mind. I’d appreciate any feedback:)