Learning is easy. Find a friend with a manual transmission car and ask for some lessons.
To really perfect it though, you need to drive in traffic and so forth for a while in a variety of conditions. It isn’t hard, it is just something that gets easier and easier the more you do it (like most things), until eventually it becomes like second nature. You won’t need to think about what you are doing, and you will never forget, like riding a bicycle.
BTW, if you visit Europe, chances are your rental car will be a stick. Easier to just learn how to drive a stick and be able to drive anything than to take the chance that they might not have ANY cars you can drive on the rental lot (because they only had two or three with automatics, and they’re already taken).
