Good news for you, anbar!
We have a demo account with pre-entered data in it. It's best for your practice since its Multicurrency feature isn't turned on yet. This means you will really have to start from the beginning.
To turn on Multicurrency:
You can also check out the article about Multicurrency. It has a list of articles about that feature, too.
Wishing you more clients from all over the world! If you'll need help in the future, feel free to visit us back in the Community.