how to teach chess.

#1
"how to make the lessons the most beneficial as possible for my student"
++ Most important is that what you teach is right. Bad teaching is worse than no teaching.
Teach endgames of 7 men or less. Those are exactly known and can be taught like maths.
'In order to improve your game you must study the endgame before everything else.' - Capablanca

"how much time I should be spending training them on different topics."
++40% analysis of lost games, 30% study of grandmaster games, 30% basic endgames

"teach them positional chess" ++ Best is to work through a text book, like "My System" - Nimzovich or "The Method in Chess" - Dorfman. Math teachers use textbooks too.
Positional chess is tricky to teach. Contrary to endgames it is no exact knowledge.

Whenever you teach you learn twice with anything. Except for chess. I was told at a very young age ponds were just small and to get rid of them as quickly as possible. Terrible advice.

Sure, go here
https://www.chess.com/coaches

And ask someone. Ideally an adult with teaching experience.

OP--Based upon your post, you are already over your head.  Hope you aren't charging for your time; if so, give a refund and do it free since you have over-sold and will be learning on the fly.  Be a "training partner" not "teacher" or "coach" due to your inexperience.   This will allow you impart knowledge,  develop your resources & learn what is required. 

What is your USCF rating and your "student's"?   Why does student want a "teacher", i.e., wants to learn what?  Goals? Did student seek you?  What is your study regimen?  How proficient are you in doing self-analysis of games, not just "check what engine says"? Analysis will help guide topics.

Develop a lesson & topics plan as well as a study plan to meet student's needs/goals, not what you want to teach. Length of your services / involvement  should be defined. Sessions should be structured and disciplined. Don't "teach" a concept unless  you have a deep understanding of it.  Bad instruction is harmful.

A good coach will have a curriculum they can use from beginner to the top level they feel they can teach (usually, about 400 points below themselves).  However, they will also assess the student's weaknesses and adjust accordingly.  If you have no curriculum, you shouldn't be coaching, yet.  You may want to hire a coach for yourself to see how they structure their lessons and then develop your own from that.

If your student is a complete beginner, you can teach them how the pieces move, opening principles, basic winning endgames (QKvK, RRKvK, RKvK, RPKvRK), and basic tactics (pins, forks, deflections, etc), but after that you should recommend a more experienced coach to allow them to continue.

To give you an idea:. I know a kid who started with a coach who was roughly 1500.  After the kid reached ~1200, he started with a coach who is a 2300 NM.  Once he reached ~2000, he started working with a 2600+ GM.  You must realize when you are out of your own depth and allow the student to move on to another teacher who can help them continue to grow.

Nice

"Chess cannot be taught. Chess can only be learned." - Botvinnik

Ok Buddy Calm Down

I believe your students need to learn Only the following.

1. Tactics specially checkmating

2. Opening Principles

3. King and Pawn Endgame.

Tough crowd.