In general, do not quit your job, close your business or change your job to a lower income level to avoid paying support. The Court has the power to attribute the level of income earned prior to taking such action. You can be ordered to pay support based on your earning capacity [the level of income that you demonstrated in the past that you are able to earn] even if you do not earn that income at the time that the Judge is making the
support 
orders.
Child Support
The general rule is that child support is based on both your income and that of your spouse/soon to be ex. There are circumstances, such as where one of you were a stay at home parent, and not working, during the marriage. It is also based on how much time each of you spend with the children. There are other issues as well that make up the child support: child care, extra curricular activities, medical/dental expenses, school tuition.
It is not only your income/wages that are used to determine how much support is paid. The Judge has the power to look at all sources of income. This means lottery winnings, bonuses, RSU income, interest income, annuity income, perquisites from employment can also be considered, free rent, insurance benefits (disability, worker’s compensation, unemployment insurance). All income is fair game. Do not try and hide any of your income, it will only come back to haunt you and make you look bad.
If you are the paying parent, you do not have a right to know what the other parent is spending the money on.
As for your obligation to pay child support, it lasts until your child turns 18 or graduates from High School, whichever is later, but no later than their 19th birthday, or they become emancipated, marry or join the Armed Services. Once your child is an adult, your obligation to support the child ends, except in special circumstances if your child is disabled or is unable to become self-supporting. Also, under California law, there is no legal obligation to provide college tuition for your children, unless you and your spouse agreed to do so in your divorce.
Spousal Support [aka Alimony in other states]
This is the one area that sometimes creates the greatest amount of angst in the cases. This is especially so when it is the wife who is ordered to pay the spousal support. Gender has nothing to do with who receives or pays spousal support.
In recent years, many wives are earning far greater salaries than their husbands, so if that is you, face the reality that you will be, more than likely, paying your husband spousal support. Although it is the goal under the law that each spouse maintain the same standard of living following separation and into the future, this really is not the case. It costs more to support two households than one. Therefore, each needs to face the reality that their standard of living will likely decrease following separation, at least for a while during the separation and divorce process. This does not mean indefinitely, though.
Talk to an attorney and find out what your obligations may be regarding your personal situation, don’t presume that what you have heard about other’s matters will happen in your situation.