No Oxford comma in German: http://german.about.com/library/weekly/aa031901b.htm
You can use "von" if you want to say e.g. "I fly from Germany to France" -> "Ich fliege von Deutschland nach Frankreich". It marks the start of a direction. But else if you only want to say something/someone is from this country, you will have to use "aus". Without context I would always choose "aus".
All nouns in German have certain genders, it is the only difficult part for me, because most of the time there is no way to tell what gender a noun is. A good strategy is to learn the noun and article together, like instead of learning "Haus" (House), you learn "Das Haus" (The House). Hopefully this helps, happy learning.
I did some research on it and it turns out, country names without articles are mostly neuter, except in cases where the name is a plural, such as in: Die Niederlande (Netherlands), die Philippinen (Phillipines), oder die USA. And some less common ones have masculine genders: der Kongo, der Vatikan, der Iran (The Congo, The Vatican, and Iran). So in most cases it's just Das.