Hello razakazmii, "along" is used as an adverb or a preposition, as described here (source: englishgrammar.org), and it seems you are asking about its use as an adverb. In your sentence (and probably in most adverbial contexts) it is optional. If you include it, it doesn't change the meaning, but it makes the tone slightly more conversational/informal/friendly. So if you want to sound formal/official, leave it out. If you want to sound friendly/conversational, you can include it.
Why are you bringing foreigners (along) with you? (Sounds more formal without "along", sounds more conversational with "along")
There's a lecture at the university tonight, would you like to come (along)?