Cool, it's really neat to see these kits here on the site, I've built one and enjoyed it and have a few more in my collection.

Josiah & Terry have some good advice there. You might also want to search some of the how-to tips here on the FSM site, lotsa good advice there too.  

Agreed, seem lines are a problem and mis aligned or bad fitting parts also a an issue. I think cleaning up the parts and test fitting them "before" glueing will make a big difference in your construction. When you remove a part from the sprue, these connection points need to be sanded or scraped to smooth it out. Everything starts with basic building techniques, theres a lot instructional videos and books out there that would help. Stay with it, we're always learning.

A good start, I like the soft edge camo and I think the machine gun turned out pretty good.

On future builds: Filling in gaps such as the one on the front of the tank, where the top and bottom hull meet will improve the quality of your builds, as well as removing excess plastic from flash or seam lines (example, that long line on the bottom of the barrel or on the end of the log).

Another suggestion I'd give you is to try some different methods out to give the model some "depth", I think the easiest way to do this would be a wash.

These are just some easy things to do that I think will improve the overall quality, I look forward to seeing some other models from you soon!