The short answer for beginners
A beginner deepthroat course should teach three things in order: calm breathing through the nose, a relaxed jaw and tongue, and a gag reflex that is trained in small steps instead of pushed through. The OnlyThroat Academy packages that as a 30-day plan with six core courses, so every night you know exactly what to practice and when to stop.
You do not need experience, special equipment on day one or a partner. Most beginners start alone and bring the skill to a partner in week three or four.