What is the best way for a new Muslim to distinguish between the two groups of Muslims: Ahlus-Sunnah wal-Jama'ah and others?

The path of Ahl al-Sunnah wal-Jamaah is the path that must be followed because it is Allah's straight path, which the Prophet clarified with his Sunnah, and upon which the Companions, who transmitted and conveyed the Sunnah, proceeded. The Prophet, peace and blessings be upon him, informed that his nation would split into seventy-three sects, all of them in Hellfire except one, which is "what I and my Companions are upon today," or "the Jamaah," which confirms that the path of salvation is the path of the Prophet, peace and blessings be upon him, and his Companions, and it is the path of Ahl al-Sunnah wal-Jamaah. Whoever deviates from it is from the misguided sects.