So far those two photos look like test shots, like you were just trying out your camera by shooting out of the window. So nothing much to comment on. If #2 was meant to be a real attempt, then my comments are:
1. Technically, the whole picture looks a little under exposed. Unless you were aiming for the silhouette of the building. But I think there was not enough light in the sky to give enough contrast for an effective silhouette pic.
2. As for composition, I can't figure if you were more interested in the sky or the building. If it was the sky, then the building just sticks out like a sore thumb. On the other hand, if it was the building you were after, then adding more of it would have added more interest (perhaps a portrait format?) as it is, the chopped off building does not have a very unique form to make a good silhouette.
3. yes this one is a little clearer, but there is still some shake in it (unless thats a tree swaying in the breeze on top of the building). If you do not have a tripod but still want to use slower shutter speed, you might find these tips useful.
a. If outdoors, try supporting the camera on a steady object. eg parkbench/table, low fence, lamp post (my favourite, press the camera firmly against it), bird bath, water fountain.....well you get the picture.
b. If there is nothing around but a building behind you, try leaning against the wall, hold your breath and click.
c. If If there doesn't seem to be any of these things around (quite unlikely unless you are standing in the middle of the road or in the middle of the desert), then try sitting or half kneel, keep the camera close to your body and again hold your breath and click. If you have already gone through NS, you will know these techniques already.
d. Finally, if you really need to stand then, adopt a comfortable shoulder wide stance with one leg forward, strap the camera as tightly against your eye with the camera strap hold your breath and...well you know.
The list starts from the most steady to the least, so you will have to increase your shutter speed a little as you progress down. Even d. should give you a more steady picture then simple hand holding since your neck is definitely steadier than your arms.
Hope these tips help. But the best advice is to go get a tripod. No need for those expensive ones (unless you are thinking of progressing to a DSLR) just a simple one will work wonders.