I think you made a great choice to learn Hiragana and Katakana first. Personally, I think you should learn some basic grammar (either from a textbook if you have one of from the internet) and then tackle Kanji when you're comfortable with the fundamentals. Usually the words that are used in the basic exercises (わたし、たべる、きょう、がっこう etc) are repeated frequently, so you can start by progressively learning those kanji first. The other option is to wait a bit and dedicate yourself to a kanji-focused book (there are a ton out there) and learn kanji that way. The thing about these books is that they sometimes make you learn more than you need (like a bunch of readings that only appear in a single word) which I feel is sometimes discouraging. At any rate, kanji is about long-term learning, you can't cram it like kana because there is simply too much and I find it more efficient to study it "in parallel" as you learn the basics. However I'm just a learner like you, and I have been using a mix of these strategies so I can't tell you which one is best, just do what you think best suits your style!

Some people told me to avoid kanji when first starting out and others suggested learning it right aftet mastering hiragana and katakana. Personally, I started learning kanji along side vocabulary, but I didn't focus on it. For example, I learned words, how to pronounce them and what their meanings were. I could figure out how to write them in hiragana by the pronunciation. I would look at the kanji reading for words just to familiarize myself with them. That way when I saw the character, I also knew what it was and how to pronunce it. That being said, I wasn't really able to write them down on my own. I was only good at recognizing the characters - which was fine for me, because my main goal was just being able to read books and signs and speak and listen. So I didn't focus on writing kanji. Yes I believe it made it easier to learn how to speak because I didn't divide up my time to study endless kanji, but I had to eventually get around to studying kanji legitimately eventually. I don't think there is a best pathway to learn the language, because everyone is different, and has different goals, preferences and different skills and weaknesses. As long as your learning and making progress I say do it the way that works best for you.

preparation materials for JLPT-5

Thanks Henrik for you advice ! I will for sure check out these Genki book which ppl are talking about because its not first time today for me to come across this name and i already saved link you gave me for later :) Thanks

But there are of course other paths that you could take. Some tips: See kanjis as many small pieces (radicals) put together into one big character. Each of these radicals has a certain stroke order. Which makes writing the kanjis not as hard since you have those guidelines. http://www.guidetojapanese.org/blog/2014/06/23/you-cant-learn-kanji/ Online jisho, coupled with Dramas and anime if you're into that, is an excellent way to pick up new vocabulary and you know... listening practice and speak patterns. Good luck!