is there a way to make text show in the chat
What do you want to do with the text?
You can use it in notification blocks and text blocks.
You cannot put it on the bottom right/left side of the game unless you rely on a chat system.
is there a way to make it so the thing that says when you knock someone out say something else
This guide has that and even more features.
I bookmarked this in case someone asks this kind of question again.