If 2 parents decide to move to another state at spereate times can the other stop child support if theyu decide not to

Since there is already a child support order in place, you should get the court's permission to move the child to California. It sounds like there will be no objection from the father, but this will give him a chance to raise any objections. This will require that you file a motion with the family court.
Once you've done that and move, the state governments will cooperate with each other to enforce the child support order. He will not be legally able to simply stop paying child support because you've moved.
Since you will have gotten the court's permission to move the child out of state, Boyfriend will not have any standing to demand you to bring the child back to Wisconsin.

Get a family law attorney to help you with this - it's not horribly complex, but it's important to get it right the first time!