You might want to spend more than just 2 days "lurking". As you have noted, the Arduino world is somewhat complex and widely applicable to many different projects. Spend some time looking through the Exhibition/Gallery section to see what other people are doing with Arduino.
There are many variations of Arduino because it is "open-source" and many people have different notions of what would be useful. That is a good thing. It gives you many options so you can select something that best fits your project.