How can I link the M/F tab with a tab the would correlate to a m/f weight class tab?

for example:  men and women have different weight classes they will register for and I have a tab that requires you to fill in Male or Female but, then I need to gather what weight class.  I took the "required" mark off the weight classes because, lifters when registering had to fill in both the men and women tab and not just for their sex, understand?

If I have understood you correctly, you want to use the value from the drop down field for the sex at the beginning of your form to set the weight class field.

You can do that by creating the condition on your form that will hide the field for weight category for sex that was not selected at the beginning of the form.

Click on the Conditions button in the Form Builder.

Follow this guide on how to set conditions for your form:

Fields that are hidden won't be required. 

Please let us know if this solves your problem.

Did you go ahead and perform the condition to my document? Do I need to apply this or is it done already?

The condition in my colleagues example was set up in a clone of your form.  You would need to set the same up in your own form.