How to copy a level into another level

Hi everyone,
I am completely new to UE (completely new to programming in general!). I need to change a task, which someone else programmed, and need to add more levels (Level 30-60) to the navigation game they build.
I tried to copy a level (Level 20) and paste it into my Level 30 folder (in the content browser) and it worked somehow, but every time I click play for the copied level 30 the level starts with Level 20. Do you know where I should be able to change that? In the blueprint “My Player Controller” I found the option “Level Info Array” and created new elements (Level 30 etc.) there. But still, the copied level 30 seems to be somewhere connected to Level 20.
I know my UE knowledge is even too little to describe the problem properly but if someone has an idea I would be super grateful! THANKS IN ADVANCE! :slight_smile:
Best,