What if you want to have a baby but you or your husband has an std?

Depends upon the std. First both of you should get tested. Then follow up with your physician to discuss the effects on pregnancy based on the std.
Treat if possible. You or your husband should have the std treated if possible. Without knowing to what std you are referring, I cannot tell you more other than to seek treatment to minimize or even eliminate risks to yourself and your future pregnancy. You or he should also take steps to avoid re-infection with safe sex practices.