Sure you can!
Underneath the poster is the ø symbol. Click ø and then choose, Yes, Hide It! This will hide this show from your progress and the Up next to watch on the dashboard.
To unhide something just go here… https://trakt.tv/settings/hidden
See here for details… How do I hide shows from my Progress or Calendar? How do I restore or unhide them? : Trakt
You can also hide individual seasons on the progress page.
Not at all! I hope this helps! 