Where are you getting it cause everytime I try to download it from EA's site or somewhere else the file is screwed,starting to give up on getting it
Today is not like most days. Remember that today is the release day of Generations, which also means a new patch level has been released.
The significance of this is the fact CAW is patch specific. When you download it, it also requires the latest patch for TS3 to be installed.
My advice for you is to wait a week or so before downloading and installing it. In the big picture, that doesn't really matter since you must also be aware that you can expect to spend a long time working on a world. I'm talking anywhere between weeks to months. That's how long you can expect to work on a world that looks very nice.
In another post, you said that you were pretty new to all this. Therefore, in the meantime I would recommend trying lot building (like houses, community lots, etc.). Some of the same concepts still apply, like decor, terrain paint, etc. However, lots are a much smaller undertaking. Each person is different (experience, amount of time available, etc.), but I find I can make a regular, mid-range house in a day or two. Much faster than weeks or months.