No, there is no such thing as a Level-1 license or course. This is part of an old numbering system that DPS has never addressed or adjusted since. The Level-1 was when DPS used to require everybody that worked at a security agency be licensed even if they were non-security personnel, such as a receptionist or dispatcher, etc.; the term was “Employee of Licensee,” and is no longer required of non-security personnel that works for a security guard company.
As a part of the online Level-2 Non-commissioned class that used to take place prior to 2010, it was split into two parts: Level-I and Level-2 (we never understood the thought behind it either). As of now, there is the Level-2 Non-commissioned, the Level-3 Commissioned, and the Level-4 Bodyguard.
TCTA provides all classes: Level-2 through Level-4 including Handcuffs, Baton, Pepper Spray, & Conductive Energy Weapon.