To determine what lightsaber form you are, there are several quizzes available online. Here are some of the search results:

• Playbuzz has a quiz that asks seven questions to determine which of the seven combat forms is best for you.
• Quotev has a quiz with ten questions that will determine what your lightsaber form would be if you were a Jedi, Sith, or Force user in the Star Wars galaxy.
• FX-Sabers has a forum post where users discuss their favorite lightsaber forms based on their personality.
• GoToQuiz has a quiz that asks questions about your preferred lightsaber combat style, emotions, and ability to deal with blaster-wielding foes.
• Rum and Monkey has a quiz that asks questions about your preferred attack style, speed, and opponents weapon.

You can take any of these quizzes to determine what lightsaber form you are.