Taxi rank is standard in the UK (I think it is "stand" instead of "rank" in the US) and "taxi", "cab" and "taxi-cab" are all the same thing ("taxi" is a bit more formal, "cab" a bit more colloquial), so your sentence is fine, except that "at" would sound more natural than "in". Because the words are so interchangeable, I would probably use them both to avoid such close repetition, so: "It is easy to pick up a cab at the taxi rank" or "It is easy to pick up a taxi at the cab rank"

Yep, you would just say can to avoid repetition You could also say it is easy to pick up a taxi in the rank

Cab and taxi are interchangeable. But I’ve never heard of a taxi tank.

sure, I don't understand the phrase, but the english is correct, if that helps??