People don't have enough experience, they get married too early, without having lived enough time together.
First, you need to know life well and enjoy it well before getting married. One should not enter into marriage until one is an adult. You need to receive proper education on what responsibilities you will have to fulfill in your post-marital life and the responsibilities you will have towards your wife. You must also learn how much responsibility you can take on for your children after marriage, both before and after marriage.
Enjoy life before getting married like how? do you mean that people who are married don't enjoy themselves?. Marriage is an institution that no one can graduate from it because you keep learning from each other all through your married life, and for someone to be at peace with their partner they must have the spirit of tolerance because these are literally two strangers that have agreed to live together which means it can even take you both a lifetime while trying to know and understand each other. However, husband and wife must understand that in the quest to build the family, it requires a concerted effort and not only from one of the parties because that is basically what is killing a lot of marriages now due to the fact that the responsibilities is being channeled to one of them which is mostly the man.