how can i move an entire level together, so that i don’t have to move every single obstacle individually?
Hello!
It is quite simple: On a computer, you hold down the Shift key and use the left mouse button to select a rectangle, just like in a drawing program. On a mobile phone, you can use the virtual Shift key in the bottom left corner of the screen instead of a physical key and perform the same operation (multi-touch). This is also explained in Candlipedia in the “Level” chapter.