Does "get used to something" have the same meaning as "get accustomed to something"? Can I use these expression interchangeably?
Yes, to "get used to" something and "get accustomed to" something have the same meaning. You can pretty much use them interchangeably, however, there is a slight difference between these two phrases. The phrase "get used to" is much more casual and informal than "get accustomed to", and is more likely to be heard in daily conversation. To "get used to" is also much more common, especially in English spoken in the United States. So while they have the same meaning, you may not hear people saying "get accustomed to" as often, unless they are speaking in a formal setting.