Ok it is important to keep it factual at Court, the LL is entitled to get their property back, but at the same time, you are entitled to your rights as a tenant if they haven't got it right.
If your tenancy started AFTER October 1 2015, then there are lots of technical requirements the LL has to get right. Gas Safety, EPC, How to Rent Guide.
(if it was before there are different rules)
The s21 has to give 2 full months notice, if it was posted through the mail, it is deemed served 2 working days after it was posted, which can mean that a full 2 months was not given in some cases and the the claim could be dismissed.
If they protected your deposit, they also have to have provided you with the "prescribed information" such as the certificate, leaflet and details about the scheme. Possession claims can fail on this point.
The claim form also has to have been completed correctly, if the LL has done this some themselves, then they often get it wrong, the hearing could be adjourned to allow the LL time to amend, (which gives you time to seek legal advice and representation -if you are eligible for Legal Aid) or it can even be dismissed.
You sent in a defence, which is why there is a hearing. Any further defence can be raised at the hearing, that's ok.
If there is no Court Duty advisor available, it is ok to explain to the Judge that you didn't get time to seek legal help and can ask for an adjournment (especially if there is doubt about the validity of the notice re above) to give you time to do this.
The Court doesn't have to agree, but will do usually if there is doubt, as Judges know that legal advisors/solicitors working under legal aid contracts for housing are in very short supply.
IF there is no defence , then PP was correct, you can ask for 42 days before possession is order under exceptional hardship, ie you have nowhere to go, health issues, finances...
Please note- this is general guidance only to give you some pointers for tomorrow as I do not know the full circumstances and have not seen the paperwork but I hope it helps, even if buys you more time.
PLEASE ask to see the the duty advisor. This is what they are there for.