Assuming you have a vacuum with the appropriate attachments:
Start by unplugging any cords that might be in the way. Move any furniture that may be blocking access to certain areas. Begin by vacuuming any visible dust and dirt on surfaces such as shelves, dressers, and chairs. Be sure to get in the crevices and corners. Once surfaces are clear, move on to the floor. Start in one corner and work your way around the room. If your vacuum has a setting for different types of flooring, be sure to adjust it accordingly. Once the floor is done, vacuum any remaining areas, such as under the bed. Don’t forget to empty the vacuum bag or canister when you’re finished.