It's easy.
Check out any of the "Tierheime" here in Munich and surroundings. Just Google "Tierheime München"
They will check out your circumstances. ie suitablility, marital status, location, space for a dog, knowledge of animals.
They also offer free courses on how to handle dogs.
Your dog will be given all the initial shots by the dog's home and you then have to look after the passport details and further shots yourself.
Have the dog barcoded (around €35,00) and then European travel is relatively simple.
The dog's home authorities will call on you unannounced annually to see that the animal is being well looked after.
Insurance is important and will cost around €150,00 annually.
Depending on the size and breed of the dog you can expect to pay around €100,00 annually for dog tax.
Then you get a tag for the dog's collar which must be visible on the dog's collar when you are away from home with the dog.
I'm sure you've already looked into food costs which are always turn out to be much higher than initially imagined.
When all that is done expect to have to invest about three hours a day with your dog, depending on size, but in return you will get 24 hours a day of love, loyalty and unbridled devotion.
You will have fewer therapy bills, the dog is your therapist, you will be healthier, you will meet a wide and interesting array of other dog owners and you will become a happy well-adjusted lady.
See my website for a page entirely given over to my doggie.
If you need any other help/advice, PM me.

edit:
Oh yes, try NOT to buy a puppy. there are loads of doggies out there who need homes. Buying just encourages unscrupulous breeders.