What do I need to get into using Unity? Do I need some knowledge in any language in particular? Can I just get to know the program with tutorials? What would you recommend?
The only knowledge you need is how to operate your web browser, read English and a link to the Unity Manual. (Judging by your question here, I think you have the first two).
From there, you can learn everything you need to know about what you don't know yet. Pick it up and learn as you go with tutorials and further searches on the internet for the things you're not sure about.
I created a course for beginners using Unity 4 you may be interested in on Udemy. You can find more info about it here https://www.udemy.com/unity-tutorial/.
Welcome to the Unity :-)