"a door and a garage"
The conjunction وَ (wa) always attaches to the next word. It's a proclitic, like the Hebrew וְ־ (v'-) . You can think of it as a prefix if you'd like.
Not in all Arab countries. There are actually 2 competing standards for this. We, in Lebanon, put a space between وَ and the word after it, and I think it would be better for the course makers to adopt that standard in this case, because it's a lot easier for beginners to learn, and it makes adding hints and tips under words a lot easier too, because people can hover (or click) on وَ separately.