How can i tell if my foot is broken/fractured/sprained?

I was walking down the stairs and my right foot came down on its side and i think i heard something crack. It hurts really badly and i can barely walk on it. I can feel this bump on the right side of it so i thought it was broken naturally but i dont have much experience with broken bones so i don't know. It hasnt swelled yet but im not sure how it will look tomorrow. im probably going to get it checked out but i wanted advice now. should i put it in an ace bandage or just use the RICE procedure? thanks!