After the introduction sequence, walk over to the spinning floppy disk and save your game if you want. Then jump to the door and exit.
Once outside the room, proceed left along the path. Avoid the spikes along the floor, as you are too weak to survive a hit from them. Avoid the bats and the critter and proceed along the path until you reach the end. Enter the massive stone lion's head.
Inside the lion's head, talk to the hermit gunsmith if you want, then take the Polar Star from his chest. Follow the path back to where you came. Shoot the enemies if you want for some quick exp or health. Once you reach the save point, you can go back in and save or continue along the path to your right. Shoot out the breakable bricks then defeat the critters. Watch out for the door, it's a mimic (actual name: cursed door) and if it hits you, deals four damage and probably drains what little exp you have for your polar star. it can only hurt you if you touch it though, so just shoot the door out, then exit the area.