If he is digging dirt and refusing access that could help you. The courts generally don't like parents who do that. Most of the dirt he comes up with is likely to be irrelevant anyway. It doesn't mean you'll get residence, of course.
As Sassa says, the court will help you if you are representing yourself.
The directions hearing should be short. The object is to clarify what issues are in dispute and/or need further investigation. It should come up with a timetable for dealing with your case. It is possible the court will make an interim order if they think an immediate decision is needed in your child's best interests, but that is unlikely.
You may be expected to make an opening statement. This should be a simple, clear explanation of why you are applying for residence. It doesn't need to be long. You could simply read out what you put on Form C2 regarding your reasons for applying and plans for the children.
Don't worry about legal niceties. As long as you are polite and respectful to everyone (including your evil ex, I'm afraid) you will be ok.
Make sure any questions you ask are not long winded. Similarly, if you are asked any questions, make sure your answer is not long winded.
You can ask the judge for assistance with anything you don't understand. If your ex has a lawyer, the judge will not allow the lawyer to intimidate you. Indeed, the judge will make sure the lawyer explains everything to you clearly.
You need to get the court's permission if you want to take a friend or relative into the hearing to give you support.
Your supporters can't give evidence unless the court has given them permission to act as witnesses. If they are witnesses they will not be able to sit in the court until after they have given evidence. You probably won't be calling witnesses in the directions hearing but bear this in mind for later hearings.
Good luck.