It's a fine attempt and I especially like the abstract (#3). I also really like the tones of the sunlight reflecting off the building on the first and last ones.
If you're looking for suggestions, I can give you a few pointers of how I'd do this:
- Perspective - It's certainly not necessary to show with corrected perspectives. But if you don't, then I recommend that you deliberately exaggerate the keystone effect (that look where the walls look like they're falling away from you). The way to do that would be to get up next to the building and close to the ground, angled upward. If you do want to keep the verticals straight and don't have a tilt-shift lens (or PP software like lightroom), the way to do that is to just make sure you're holding your camera completely level at 90 degrees (i.e. don't tilt it upwards). Your lines will be straight but if you're too close to the building, you'll cut off the top of it and get too much of the ground. So you'll have to back up a bit and then crop later.
- Straight vs. Crooked: shooting a building at an angle can be a great way to showcase it - especially if you're taking a detail of it. Your shot #3 is a great example of how to do that successfully. But your first and second shots are slightly crooked, leaning to the left (the second one more than the first). I'd rotate the images to make them straight.
- Context: I like to see a little context for the building, to see what's around it and how it interacts with other buildings, sky, landscape, etc. So for example, in shot #1, I'd have backed up a bit and also angled the camera slightly more to the right to perhaps get the sunrise/sunset in the shot. Use the sky to add drama to your shots, because the color variations and clouds provide interest and compliment the building. It's also good to use cars and people to show scale whenever possible. Shooting at a slow shutter speed so they're slightly blurred helps to avoid them becoming the focus of the shot.
Anyway, hope that helps. Don't be discouraged, Dan! I look forward to seeing what you do next. Applying your creativity and style to architectural photography would really be something to see, indeed!