idk if im stupid but i have no idea how to leave the tutorial
You wake up in a small office at the start of the game, a few lockers around you. You leave into the hallway and to your left there's some cardboard boxes, by Left-Clicking you can pick them up and throw them around, you can then progress down the hallway, following the blood trail to the door, enter that office and talk to the security guard closest to you. He'll give you a Warehouse Key Code, when you're ready leave the room from the door you entered it and turn right, at the end of the hall you'll see the Warehouse Door (and the other hallway you came from past the cardboard).
Once you enter the warehouse, walk down the steps and hug the left-most wall, there'll be a big loading dock style gate but you can't open it yet, instead go through the door to the left of it. You'll enter another hallway with two doors, one you can't open from this side that leads to a security office and the other will never open. Past those doors are some cardboard boxes, you can pick them up and move them using Left Click to grab (controlled by mouse, be careful) and you can then choose Left Click to Throw it or Right Click to drop it, move the boxes in front of the Vent Cover and climb up to the vent cover, which you can then grab in the same way, tossing it behind you in the hallway. Crawl through the now open vent to the other vent cover (Click it and then drop it or throw it, your choice) then pull the level in the security office. That lever now lets you open the Warehouse Loading Gate and allows you to leave the Complex!
This game is very "Metroidvania", you'll be back-tracking a lot and the puzzles can be fairly tricky, I hope you enjoy the game!