A bed. I mean mattress is ok but eventually you want a bed. If it’s a studio, you want to save space. Ikea has beds with massive storage drawers. The one we have also has shelves on the side and a shelf over headboard. You can fit everything in that storage. You don’t need dresser or shelves. It fits everything!!!! Ours is full size as it’s in the spare bedroom for grandkids etc But my daughter has one with less storage and twin size but it opens up into full size if need to. They aren’t expensive. But they are life saving beds for small places because of storage.