space between entry title and date

Do you have a link so I can take a look?

The .entry-title is on line 1086, you can add margin: 0; since the title uses margin bottom from this code h1, h2, h3, h4, h5, h6 on line 324. So add the margin: 0 to the entry-title like this –

.entry-title {
    color: #b1df97;
    font-size: 36px;
    font-size: 2.25rem;
    font-weight: 400;
    line-height: 1.3;
    margin: 0;
    padding: 0 20px;
}

Then look around line 2206 for this for everything else –

.entry-header .entry-meta {
	border-bottom: 1px solid #eee;
	font-size: 12px;
	font-size: 0.75rem;
	font-weight: 400;
	margin: 0 0 10px;
	margin: 0 0 1.25rem;
	padding: 20px 20px;
	text-transform: uppercase;
}

Edit the first 20px in the padding since that controls the top and the bottom of the padding. You can lower this until you get the result you want.