Help getting started with scripting in TMP

Hello! I feel like I’m going crazy, because I can not find out how to edit the text of a Text Mesh Pro object through scripting. I’m specifically looking at UI. I’ve looked through the FAQ and documentation, but everything is telling me to have
using TMPro; but it isn’t recognized by Unity. I’m using Unity 2018.2.15f1
Can I get some help?

If the namespace TMPro; is not being recognized, make sure you update Visual Studio to the latest release.

I would also suggest you take a look at the example included in the TMP Examples & Extras and the many scripts in there which should be a good source to learn from.