If you want to do it the easy way without messing around with HTML:
1) In your email, where ever you want to add the social follow icons, insert a table. Your icons should be equal in size. Split the columns to the number of icons you're inserting. Make sure to upload the icons to Design Studio. Get the URL links for the icons once you upload them to Design Studio.
2) In column one of your table in your email, click on the image icon , a pop up window will appear, paste the icon URL (let's say Facebook), and add the alt text tags. Then click on the Facebook image again, and then click on the link icon and add the link to your company's facebook. Repeat this for the other social icons until you've populated your table columns with the social icons that you want to insert.
Really simple no HTML required.