Don’t delete your texts and emails with your ex - those messages can be some of the most important evidence in your case, and making a habit of keeping everything can change the way you communicate for the better.
Does my ex have to exercise the visitation provided in the parenting plan?
Typically, a parenting plan will outline visitation beginning with a phrase along the lines of "During the term of this Parenting Plan the non-custodial parent shall have at a minimum the following rights of parenting time." If so, the non-custodial parent is not required to exercise his or her visitation time, but is allowed to do so.
Does each parent have to pay for half of extracurricular activities?
Extracurricular activities can be fairly minimal, or can be thousands of dollars per year, per child - especially if the word "travel" is involved. Because the costs are usually on the low end for younger children, parents often don't consider the costs at the time of separation, but only when they've reached their full, teenage levels.
Does a parent receiving child support have to account for how the money is spent?
How are child support orders enforced?
Where will my case be?
There are two issues surrounding where a case will be filed - jurisdiction and venue. There is a course in law school dedicated almost entirely to these issues (civil procedure), so unfortunately I can't give a comprehensive answer to the question that suits every situation. The general rule is that cases must be filed in the state and county where the person you're filing against lives, but divorce and family law have more exceptions to that rule than probably any other area of law.