The time it takes to reach the level cap in World of Warcraft can vary significantly depending on several factors. These factors include your playstyle, experience with the game, the leveling content you choose, and whether you're using any experience-boosting items or features. As of my last knowledge update in September 2021, here are some general guidelines to give you an idea of the time it might take:
Experienced Players: Experienced players who are familiar with the game and have heirloom gear (special equipment that boosts experience gains) can often reach the level cap much faster. Some experienced players can level a character to the cap in as little as a few days of gameplay.
Casual Players: Casual players who play a few hours a day and take their time exploring the game world, completing quests, and experiencing the storylines may take several weeks to a few months to reach the level cap.
New Players: New players who are learning the game mechanics and taking their time to explore and enjoy the world may take several months to reach the level cap, especially if they are new to MMORPGs.
Experience Boosts: WoW periodically introduces experience-boosting features or items that can significantly speed up the leveling process. These can reduce the time required to reach the level cap.
Leveling Content Choice: With the introduction of the level squish and the revamped leveling experience in the Shadowlands expansion, players can now choose which expansion's content to level through. Some expansions may have faster or slower leveling paths.
Group Play: Playing with friends or joining a leveling group can also make the process faster and more enjoyable, as you can tackle quests and challenges together.
Efficiency and Optimization: Efficiency in leveling, such as choosing quests and zones with optimal experience rewards, can also impact how quickly you reach the level cap.