Many people representing themselves in court, known in legal parlance as pro per or pro se, think that once they file the lawsuit then all they need to do is show up at the hearing.
While certainly that is sometimes true, it is an area that truly shows where someone who is pro se can suffer a case ending calamity compared to someone with a lawyer.
It is very, very rare that a lawyer will allow a case to proceed to a contested hearing or a trial without serving discovery on the other side.
Just as a lawyer wouldn't go to trial without knowing the law on a case they also will not go to trial without knowing the facts and the only way to learn what facts the other side in a case will rely on is by doing proper discovery.
Discovery allows you to identify witnesses, find out what the other side's story will be, and spot any holes in your case that need to be filled in as well as what weaknesses the other side has that can be exploited.
A case can be won, or lost, in discovery, and anyone who proceeds to trial without doing it properly can count themselves lucky if they win.
However, it is not only important that you do discovery but also that it is done properly. Asking questions without a plan does nothing except make more work for you and your opponent.
If you've never done discovery then you might want to take a look at the Guerrilla Guide to Written Discovery for pointers because it is much harder than you might imagine.