Welcome! I bought my FiST 8 months ago; best purchase I ever made. It's the Miata of hot hatches. In my experience, this has been a really accessible community. Stick around this forum and the r/FiestaST Reddit and you should be covered forum-wise. There's not a lot of jargon floating around, considering that there's only one gen of the ST here in the US, but you'll pick up things here and there.
Considering it's a Ford, things are bound to go wrong here or there, but the 1.6t is a disturbingly stout engine, considering it's an Ecoboost. Just give her love and she'll last you a long time.