I have been married for 18 years. I have 3 kids. We both are agreeing on a divorce.
2 kids want to live with him. 1 wants to move to another state with me. Question is will I have to pay my husband child support?

It all depends on what kind of a settlement you work out between yourselves. There is no hard and fast rules. Who makes the most money?

He makes a lot more. When I move I will have to find a job.

This is a question you ask of your divorce attorney. They will know the specific situation and be able to advise.

I cannot afford an attorney

You can't afford not to have an attorney. If this is not an amicable divorce, you will lose without one. You should be able to get your ex to pay for the attorney as part of the divorce settlement.