After the Arabic tree, what next?
Where should I go next to continue learning Arabic and to keep practicing?
Just try out any language exchange website. There you might find a nice native speaker who wants to learn your mother tongue and start a language exchange. In this way you can practice your words and learn even more through texting or voice messages. And besides this just start with small videos on Youtube. There are many with subtitles available.
Here are a couple of websites that could help (these includes websites that help you to improve your skills, help to start learning Arabic, and some language exchange websites)