I would highly suggest hiring an attorney. If all cases were truly so simple that all lawsuits could be done pro se, there would be no need for anyone to attend law school or pass the bar exam. Every case is different--your question does not specify the type of hearing, type of evidence, or issues involved. I do not mean any of this with disrespect, but you should hire an attorney. Moreover, most areas in Texas have a legal aid office, you may qualify for services there for free or at a reduced rate. In addition, sometimes the local bar associations offer clinics where private attorneys volunteer their time to take on these cases pro bono. I'm sorry I could not be of greater assistance.
Your question is too general. If you cant afford to hire an atty to represent you in the whole case, you would be smart to at least buy an hour or two of atty time to explain whatever type of issues you are going to be dealing with, what forms are needed, and how best to proceed in presenting your case. You may learn that what you are asking for is very reasonable and will be well recd by the court, or you may find you have unrealistic expectations. I look at this as a reality check.
Presenting evidence and what evidence to present is something that confuses even veteran attorneys and can get them to arguing. If your ex or spouse has an attorney and you don't, you're at a severe disadvantage. Dallas has a lot of affordable attorneys. Call around. See if any will take a payment plan. It's worth it.
I agree with all of the other lawyers who have responded.
I am a lawyer, but I would be no more willing to represent myself in family court than to perform brain surgery.
Your question sounds simple and straightforward, but the answer is anything but simple. Lawyers study and work for years to learn these things. You cannot learn how to be a lawyer or how to prosecute or defend even the simplest family law case on the internet. In a family law matter, there is no substitute for professional legal representation.
I suggest that you consult a Plano lawyer who is certified in Family Law by the Texas Board of Legal Specialization. There are nineteen such lawyers currently listed. Some of them probably offer hourly rates that are within the reach of folks of average means. Some may offer periodic payment plans as well. A link to the Board's website appears below.
I agree with the other answers - hiring or at least consulting with an attorney is your safest bet. However, if circumstances don't allow you to follow the advice posted previously, at least go to the closest law library (usually in the county courthouse) and review any materials available on pro se representation in family law matters. There may be commercial books, a binder of information compiled by the local bar association, or other resources available to you.