It starts with the way you copy the link, which is sometimes hard to avoid actually opening it.
Try with a right click and select Copy Link if that option exists. If not, maybe just Copy will do without actually selecting any text of the link. If all else fails, click close to the link but not on it, then use the keyboard to put the cursor as close as possible and use shift-cursor to select.
Then when you paste, do it in a field that doesn't accept links, like the title of the event. It will reveal extra characters. Remove them, copy again and paste where it should appear. After some practice with the correct copying method maybe this won't be necessary after a while.
For the events already created, you can click just before or after the link and use the keyboard to move the cursor where you want to delete the unnecessary characters.