How to level up quickly in gta online?

The only verified information concerns Grand Theft Auto V’s single‑player campaign, which follows three protagonists—Michael De Santa, Franklin Clinton, and Trevor Philips—as they plan bank heists in the fictional state of San Andreas. It describes the game's open world, but it does not include any details about the multiplayer mode, its progression system, or strategies for gaining experience. Therefore, based on the available evidence, no specific guidance can be given for rapid leveling in GTA Online.