You can do the following:
chest flys (lie on your back, arms out; lift the weights up so they meet in the middle of your body [n.b.: this will probably be impossible with heavy weights)
standing rows: stand up, weight in either hand--lift them up to your chin, and keep your elbows out.
curls--i hope you know how to do these
shoulder presses
lift the weight over your head, and keeping your elbows close to your ears, lift the weight from behind your head to above it. Hope this makes sense.
lunges--a weight in each hand, step forward and go down 'til both knees are at right angles.
Hope this helps, but for future reference a bench and more weights might not hurt 🙂