How do I auotmatically make my footer start below my paragraph box?

This is what I have in my CSS right now:
.body-p {
height: 700px;
max-width: 100%;
font-weight: 100;
text-align: center;
padding: 12px;
color: black;
font-size: 20px;
font-family: ‘Open Sans’, sans-serif;
display: block;
}

footer {
height:100px;
width: 100%;
background: url(Pictures/74H.jpg) center;
background-size: cover;
margin: -10;
padding: 5px 5px 5px 5px;

}

If you wrote code for <footer> below the code for the paragraph wouldn’t it show below the paragraph?