Becoming a multi-cultural and multi-lingual individual starts with a changed mindset. You need to fully accept that your ways of doing and seeing things are not the only way. Stop the comparison madness and be willing and ready to learn from others. This is done by giving others from a different culture a chance to show you things from a different perspective. You will be amazed at what you can learn just from allowing yourself to view things differently.
Now, why am I focusing so much on the cultural aspect? I do so because it is extremely difficult to become fluent in an other language unless you immerse yourself into that culture. You cannot have language fluency without strong cultural knowledge. Then again, why would you want to? Language is an integral part of any culture and a good understanding of the culture helps you understand when words and phrases change meaning based on context. Besides, you are learning the language to be able to communicate with others right? Therefore, it does make sense to incorporate learning about their way of life as part of your learning plan.