I've been to Belgium a few times when I travelled across Europe. Belgium has 3 official languages: Dutch, French and German. There are approximately 75% of the Belgians who are Roman Catholic and the remaining 25% are Protestant and other religions. The kids are required to learn also English at school and from my own experience I have noticed that many Belgians speak very good English and are usually friendly and helpful.
They are speaking of course German in Austria. But don't worry, if you don't know German. Many people have chosen English as second language and you can use that to get around. The majority of Austrians is Roman Catholic (ca. 78%), 5% Protestant and other religions make up the last 17%. Austria has got a high living standard and some people across Europe consider Austria an expensive country. But that's something everyone can view differently and depends also on your own income, ... and what you can afford.
Well, you might wanna have a look at the so called "CIA world fact book". Just type this into http://www.google.com
and there you'll find detailed basic information about all countries.