If you think that there is something like heaven and hell exists, you are wrong then. There is no heaven and hell. This life is actually both heaven and hell. What you sow, so shall you reap. How good or bad your life will be, it depends on your karma. If you have done something good and helped others, it will come back to you in this life. Your smallest good deeds will come back to you, so always do good karma. If you have done wrong and hurt others, you have to face all the consequences of your sins in this life itself.
Many people will question if everyone gets rewards and punishments according to their karma in this life, then beginning of the next life of every person must be the same but it is not correct. Your karma in this life will decide how your beginning of life in the next birth. Your beginning in next birth will be good If you did good karma in your previous birth and your beginning in next birth will be bad if you did bad karma in your previous birth. After that it will depend on your karma how good or bad your life will be. If a person who is born poor or has faced hardships since birth can also achieve success and wealth if he has done good karma while a person who is born rich and living lavish life can lose everything if his karma is bad. So do good karma and make your life worthy and meaningful.
This life is actually both heaven and hell.