Learning Chinese requires an ongoing commitment that many cannot sustain once they encounter some frustrations and/or learning "plateaus" that are inevitable.
I have been studying Chinese for 6 1/2 yrs, every day for a minimum of 1 hr a day. MINIMUM. Sometimes much, much more. I've only taken 2 breaks from it, when I really felt like I needed a vacation from it. I live in the USA, so of course, it is harder to acquire a command of the language since I'm not surrounded by its use at all times. Learning the language in China itself can highly accelerate the process.
I started by taking formal classes at a school for Chinese children. I continued studying on my own with my Chinese boyfriend. When I broke up with him, I kept studying on my own, and set up some tutor-trading where I'd help Chinese people with their English and they'd help me with my Chinese. That had varying degrees of success.
There's different aspects to learning Chinese- First, the writing. Each word is a different character. There is no formal alphabet, per se, though some components of the characters may be the same or similar. Seriously, to learn to read and write this language you must take it ONE WORD AT A TIME. Some people report that they memorize how to write certain characters, only to forget them a week later. It's not simply writing the characters over and over that you must do, but you must learn to mentally visualize how the character looks in order to then reproduce it on paper. Muscle-memory isn't enough, so it's a very different way of learning-- visualize first, write second.
I honestly haven't met many people who have studied Chinese as a second language who have fully mastered WRITING all of the characters from memory. I can do it fairly well, but I PRACTICE READING AND WRITING CHARACTERS EVERY MOMENT I HAVE A CHANCE, and this includes breaks at work, and at red lights as I am driving-- I keep index cards in my purse for this purpose- to see new characters and study them whenever I have a moment.
The second aspect is the conversational piece. If you are not in an environment where people are speaking in Chinese, you may lack opportunities to really gain conversational fluency. I tutor English as a second language with Literacy Volunteers and have noticed that my Chinese students have a similar problem: One can practice reading and writing on one's own, but one needs a partner to engage in conversation. You really need to FIND people who not only speak Chinese, but are good at explaining the differences in the grammar and meaning (easier said than done) to feel you are making progress in this respect.
Am I trying to discourage you? Not at all! Chinese is a fascinating and beautiful language and the challenge of it is what attracts me to it. However, if you have a GOAL of FLUENCY within a certain period of time, I think you are setting yourself up to be disappointed. Take it one step at a time. Above all, I cannot stress enough that you will NOT LEARN TO SPEAK CHINESE BY GOING TO A CLASS ONCE OR TWICE A WEEK AND STUDYING A COUPLE HOURS IN BETWEEN CLASSES. You must study every single day.
In order to pick up the phonics and the sounds of the words, I found watching Chinese movies with subtitles to be invaluable. The more I heard the sounds, the more I was able to reproduce them in my own speech.
Choose a textbook series that you like and stick with it. Some people jump from one book to another and never make progress. Now, of course, you can supplement your learning with more than one book, but try to continue studying with a textbook series that will take you from beginner to intermediate rules of grammar, etc.
Arabic is not really like Chinese in terms of the syntax. I know a little bit of Arabic and there's an alphabet, too, which there isn't in Chinese.
Final advice- Get a really good dictionary. I don't know about Arabic-Chinese dictionaries, but for English-Chinese, I have found the Oxford one to be most reliable.
Chinese is challenging, but fun. Be diligent and enjoy any small progresses because soon they will add up to big ones.
P.S- I also think "fluent" means different things to different people. My version of fluent is being able to speak a second language with the same command of vocabulary, grammar and idiomatic phrases that I have in English. For some people, it's about having a basic conversation that may not be as precise and colorful as they can speak in their native language. Only you will know in time what your aptitude is for the language and what effort you will need to invest to attain your ultimate goals.