Hello. I am just checking that this relates to a Court in England and Wales, as this is what I can advise upon.
Yes, you can definitely represent yourself and many people do and the Courts are used to it.
You will need to decide from the case and papers so far what the most important message is you want to tell the Court. I would make this your main focus.
YOu should also read the papers carefully and see if you have any questions or disagreements about what the other party has said. NB, you may not necessarily have to speak everything because the magistrate will have the papers and often says...."I see that on page X".
You will not be allowed to bring new evidence to the case, ie things which are not covered by the papers...BUT it's always worth trying to "add" to the papers. It's a lot about trial and error about what the Court will allow.
To be honest, the Courts are generally sympathetic to unrepresented parties - they know you don't know everything and all the rules and as long as you are polite and helpful if you are asked questions answer them calmly this will go a long way. You can almost use your status as unqualified as getting a sympathetic approach from the Court.
When you get to the Court, you need to find the place to check in to say you are there. Another thing you can do is to arrive early and ask if you can go in and see another hearing, eg the one before, this gives you an idea of what will happen. You can actually come and go in Courts very easily.
Whilst I don't know the nature of the hearing, I hope this general advice has been of help. I am happy to clarify anything.