I know what you're talking about, and always put your best foot forward! Don't call yourself incompetent. I have a website here that uses this technique to display the header: which.name ("Company" gets replaced by other words)

Agree with @alvivanco, typically just refer to it as animated text or fade-in-fade-out text, not sure there's a proper term for it. I can send you the code for this if you want to use it on your own website where you have control over the source code, otherwise use webflow as mentioned above.