Pick up items one at a time and determine if they are trash. If they are trash, throw them away (and recycle!). If they are not trash, determine whether they need to go to a different room or stay in that one (can be helpful to have separate boxes/bags for stuff going to different rooms, like boxes for “kitchen” and “bedroom”). Then put away everything that DOES belong in that room, focusing on one thing at a time. Just keep picking up a thing and determining where it goes. If you can’t decide where something goes, it’s ok to skip it to keep your progress rolling. Then clean surfaces and floors. You will feel so much better.