First things first,

I am a complete noob if it comes down to the frequent flyer program. But I am eager to learn.

Now I've read some basic information on how to earn miles without boarding a plane. Like getting a credit card, now of course the credit cards that give you a nice starting bonus for signing up are all American. I suppose I can only request a credit card in my own country (Belgium)?

I've already looked into the Miles & More program. You can earn miles by requesting a credit card, but there is no signup bonus, only 1 mile per 1 euro spent.

So any tips on how I can earn more miles?