The engine in your Fiesta ST-line is fundamentally different from the 1.6L ecoboost engine that comes in the fiesta ST. It would not be worth it to turbo it. You are better off selling and getting a Fiesta ST. This "tune" you speak of for your engine would likely require a standalone ECU as to my understanding, there are no off-the-shelf ways to tune the Fiesta SE/ST-Line ECU.
To give you a rough number, you are likely looking at $7.5K to properly turbo your car.
The fact that you are asking a question like this tells me you would not be up to this challenge hence my recommendation to just start with a car designed to be turbocharged.
Edit: This article is a good starting point on how to properly turbo an NA car. I found it within 5 seconds of google searching:
https://www.torquecars.com/tuning/adding-turbo.php