Add the margin-left property along with the correct value.

<html>
<head>
<style>

.hugePadding{
background-color: limeGreen ;
margin-left: 100px;
}
.mediumPadding {
background-color: orange ;
margin-left: 50px;
}

.noPadding {
background-color: lightSkyBlue ;
}

</style>
</head>
<body>

<p class="noPadding">Planning phase -></p>

<p class="mediumPadding">Execution -></p>

<p class="hugePadding">Completion -></p>

</body>
</html>]]>

Make sure to pick margin-left, followed by :, and finally 100px.