My suggestions/corrections to the text:
Last summer, *my aunt, cousin and I got on a plane and spent a fortnight in Munich visiting my uncle. I enjoyed it a lot. We visited several museums and landmarks, mostly palaces and castles, and we, also, walked in the Englischer Garten, one of the world's largest public parks.
As I can’t speak German, I had to speak English when I was there. English is the most common **means of communication amongst various different language
speakers. Throughout the world, when people who speak different languages get
together, they usually use English to communicate. Learning to speak English is important in
many areas indeed. For instance, it will allow you to become more employable in many countries
. You will have access to and understand
a great wealth of information and entertainment. Therefore, the importance of learning English cannot be underestimated in an increasingly interconnected and globalised world ***and the usage is growing for various reasons, for example, business, education, collaborative research, social media, news, films, music, books, travel, and sport.
* The same thing, but more concisely.
** Do not forget that the "most commonly used language" in the world is Mandarin.
*** Some extra information.
is the second most commonly used language in the world with currently 500 million native speakers."http://miamioh.edu/cas/academics/depart ... index.html