It is important to know that the Photo app does not "move" your photos into albums, such as Trips. The Photo app scans your photos and mirrors them into the albums that they hopefully fit into. Your original photos will always be found in the Library.
Unfortunately, it is not possible to turn off Collections. But you can press the little blue arrow to the far right next to each "album" in the list to minimize it, so that the overview hopefully appears more manageable. At the bottom, you can also select Reorder, where you can drag less relevant albums to the bottom, and more relevant ones to the top.
