>I can read kanas and some basic kanjis
>My grammar and vocabulary is like a small kid

I doubt it. A small Japanese kid can beat you in any Japanese exam. I am not saying this to discourage you or anything like that. So here are my tips and methods:

1. Get a copy of Genki 1 and 2, including workbooks. After each chapter, don't forget the extra reading and kanji exercises near the end of the book. Even if you know the grammar, do the workbook exercises. This will help you actually use the grammar.

2. While doing this, also start using Anki for vocabulary/kanji. I strongly recommend improved core 3k deck. Do it every single day. If you set the "new daily cards" to 50, in 2 months you will have learned the most used 3 thousand words and their kanji. This is important so you can actually read without looking up every single word. Trust me, it becomes bothersome.

3. Start reading after finishing Genki 1. As anon said, yotsubato can be a good start. You can use sites like jpdb.io to check if they are easy enough for you. If you find it to hard and bothersome, take a break from reading for a week while you keep studying. Then try again. Rinse and repeat.

4. While reading, you might want to create your own anki deck and add the words you looked up, along with the sentence. This is called sentence mining, and this will drastically speed up your learning, and help stop you from forgetting the new vocabulary you learned while reading.

5. After finishing Genki 2, you will be past the beginner level. You should keep on reading, and also start some other textbook like tobira.

DON'T EVER USE THINGS LIKE HEISIG'S REMEMBERING THE KANJI. It will slow you down, because you will be dedicating a considerable amount of time to kanji only. Just don't do it.

Finally, just start studying and reading. Time spent not studying or reading is time wasted.

Good luck and have fun.