Each party works to discover as much as possible about the available property and about the other side's case. Both sides will file Sworn Inventories, which list all of the couple's assets and debts. All during the discovery process, both sides are usually working to reach a settlement of the case. It depends on how quickly both sides can reach a settlement. If the spouses cannot agree and trial is necessary, it can take months or even over a year to get to trial.
Most courts require the parties to try mediation before they are set for trial.
Trial settings often get postponed. The result of a trial can be appealed if one side is willing to pay for it. Appeal can drag things out for many months or years. The vast majority of divorce cases settle before trial starts. There is no way to know how a trial will turn out.