The top and bottom have padding which adds some of the space. You can locate this in your style.css file around line 1318 –
.welcome-wide .wrap {
margin: 0 auto;
overflow: hidden;
padding: 120px 0 60px;
width: 1140px;
}
Although the majority of the space is actually coming from the Welcome Features div/section. Are you planning to use any of the Welcome features 1, 2, or 3 widget areas? If not, then that welcome features div will need to be removed. It’s not supposed to show up if you’re not using any of those 3 widgets. I’ll probably need to check your file to make sure everything is setup properly.