Swedish
I learned just the basics of Swedish, because I only started recently. It was because of our planned trip to Sweden and other Nordic countries.
My parents bought me textbooks and a dictionary and a small conversation book. I also found some free online courses - there is a lot of them on YouTube. I tried to learn as many words and basic phrases as possible. That wasn't too difficult because Swedish is similiar to German or English. I was more worried about pronounciation - there are some pretty difficult sounds in the Swedish language. I focused on understanding because there wasn't enough time to learn to speak well.
In the end I didn't really use Swedish when we went to Sweden. Most people speak excellent English there. When they saw that we were foreigners they often started speaking English even before we said anything. But my knowledge was very useful for reading notices and instructions and other written information.
We went to libraries in several Swedish cities and I bought some second hand books in Swedish (mostly children's books) and I was able to read two of them. One of them was about different parts of Sweden and in one there were questions and answers for children.
When I have time, I plan to continue learning Swedish. I already found some songs in Swedish from Disney movies with both English and Swedish subtitles and that's excellent for learning.
This is my textbook...
And one of my dictionaries...
This is a book I bought in Sweden:
Below you can see one of the songs in Swedish that I listened to several times.