"Lawyers" in Ancient Rome were generally patricians who owed assistance to their cliens. There were no formal schools of law, and the law in Republican Rome was a changeable and largely customary thing, with a considerable religious component. What's more, from 204 BC onwards, these "lawyers" were legally barred from charging for their services, thanks to the Lex Cincia -- but even before, and well after, the passing of that law, it was considered beneath one's dignity to charge for legal counsel and advice.
In short, it wasn't a profession. Roman patricians generally knew the customs of Rome, and were capable of advising their vassals, retainers, and various plebians on points of law which reflected those customs. (Where the law was codified, it was extremely clear.) Some of these patrician-lawyers were orators and made pleadings before the court -- most did not, and in most cases pleadings were made directly by the parties involved.
Also: In Republican Rome, Judges (judex) were private arbitrators. They were not officials.
So it was what we'd call a customary and amateur legal system.