Would I have to pay him alimony and will he get part of my retirement or pension plan if I make more money than him?

There are several different types of alimony in Florida. Generally, permanent alimony is unlikely in a four year marriage. Depending upon how much each of your incomes actually are, and how much the disparity is, and other factors, bridge-the-gap alimony or durational alimony may generally be possible. Rehabilitative alimony would depend upon other additional factors, but seems generally unlikely from the limited information you supplied. You should consult with an attorney if you are about to go through a divorce and address your alimony concerns with them. As for your retirement plans and pensions, generally, the portion you earned or contributed to during the duration of your marriage is subject to equitable distribution by the court. So yes, your husband would generally be entitled to half of the marital portion of your pension and retirement plans.

4 year marriage the other side will get little if anything.

You would probably not have to pay alimony, but he would be entitled to one-half of the pension which was accrued during the marriage. You need to set up an appointment with a local family lawyer.