I really want to know what happens to a Jew after his death .
There are numerous sources that discuss what the soul undergoes after death, but we will just give a basic overview. After a Jews death, the soul separates from the physical body, and is taken for the accounting that it has to give in front of the heavenly tribunal. Over there, the person’s entire life will be replayed in front of him and the heavenly tribunal. Then they will decide, based on the person’s actions in this world, what the person’s just retribution is. If the person merits entering the Garden of Eden, then the holy angles will take him there. However more often than not, the soul is not clean enough to go straight to paradise. Therefore, it needs to get “cleaned” and purified in order to merit entry. Therefore, the soul will undergo the cleaning process needed in accordance with the soul’s iniquities, to clean it so it can receive its due reward. (This is why children say kaddish for their departed parent, to help them in their time of need). After that, based on the person’s merits, the soul will be given it’s just place in what is considered a waiting area. A place of tremendous pleasure, we can compare it to a super luxurious spiritual lounge. Then, when the time for the resurrection comes, Hashem will rebuild our bodies, based on our performance of the mitzvos, and we will then merit an even higher form of reward. After that period, will come what is called Olam Haba- the world to come, which is a world that will be very different than this world. The world we will in now, is a world that is built in order for us to perform mitzvot. We have physical parents, a physical body, physical food, and of course the freedom of choice to choose good from evil, to choose to do Hashem’s will or to follow our animalistic instincts. Therefore, this world is built in order for us to work and earn our reward in the world to come. The World to Come however is created with the intention of giving spiritual pleasure, and is built in a way to give maximum pleasure, again with each person having pleasure according to his merits and actions in this world.
Dercech Hashem (The path of G-d) Section 1 chapter 3.