How can make objection to a motion in family law in florida?

You may object to a motion but before you do you may need to know whether the motion is before the court pursuant to Florida Rule of Civil Procedure 1.110, 1.530, 1.540 or some other rule, and exactly what it is you're up against. Going into it without representation is dangerous and I do not advise it.

You can file a response to the motion although it is not required. The judge doesn't look at the file until the hearing anyway

It depends on what kind of motion it is.

In many cases, a motion does not require a response or an objection prior to a hearing. You are certainly free to make one though. Filing an objection won't stop a hearing, and you can make your objection at the hearing also. Certain discovery requests can require an objection within a certain amount of time otherwise they are deemed waive. You should speak to a lawyer regarding your case. Consultations are usually free and payment plans are available in most cases.