First in your new project you want to create a new event sheet and name it whatever you like. Then, to copy and paste you just need to select all of the events manually. If you select one at the very top and then hold shift and click on an event at the bottom it will select all. (Or just use ctrl+A).
Then you can ctrl+c OR you can right click on one of the selected events and choose copy from there. Then go into your new event sheet and paste it by using ctrl+v or right click on an empty area and paste.
(you can also copy and paste sprites the same way).