I agree with Lisa, that going into the meeting with a positive mindset will help the process immensely. We should assume that the teachers working with our students are very capable, very compassionate, and very focused on meeting the needs of our child. The special education process should be a collaborative one, where the intention of all parties involved is to put the student's needs first.
Second, I think it's important that you know your rights as a parent of a student with a disability. It can be daunting to face the special education process, with all of its legal requirements and unfamiliar vernacular. One of the best ways to advocate for your child is to know your rights, understand the process of special education, and work with the team to create the best education plan for your student.
Third, do not hesitate to ask questions throughout the meeting. You may be tentative to do so, because finding the right questions to ask can be tough. But there's no harm in saying, "I'm not sure how to ask a question here, but I am unclear on the discussion that is taking place." If the meeting is a successful one in which you were an equal contributor to the conversation, you should walk away with little to no questions about how your child will be supported in the school.
Finally, I would reiterate what Lisa said above: "Remember that you do not have to make any decisions on the spot." You should not make decisions until you feel comfortable with how the decisions will affect your student, and confident that the decisions will support the individual needs of your student. Take your time, absorb the information, and call for another meeting if necessary.