Don’t know how to do anything.
Viewing post in Time Portal Paradox jam comments
You first need to click on a character or a time machine. Than you can click the orange icon above them to swap to "path editing". After that set a path using WASD and space (to wait a cycle). If you are happy with the path click the green checkmark. Than start the time simulation with "space" key.
The game description also has some gifs with gameplay which might help you further.