With that telescope, you should be able to comfortably observe:
The Moon - try drawing your own map of surface features, or finding all major craters and mares
Venus - observe the planet over many days, and see if you can notice the changing phases
Mars - not much to do here but enjoy the blurry red disc
Jupiter - probably you won't see any cloud bands, but you should be able to see the four galilean moons. See if you can find a way to measure their orbital periods.
Saturn - you may not be able to see the rings as separate from the planetary disc, but the non-circularity of it should be obvious.
And finally, the Sun(Do not look at it directly! Project the image onto a cardboard screen) - you'll see the sunspots quite distinctly. Count their changing numbers and positions over an extended period. Compare with past solar activity records. Calculate their lifetime. Try to figure out the direction of the axis of Sun's rotation.
Other than that, take a look at Pleiades and Hyades, to find out how many more stars are hiding in those clusters. See if you can observe the vague blur of Orion Nebula or the Andromeda galaxy(on the Northern Hemisphere; Magellanic Clouds in the South).