Now before I explain to you the "Sensei & Cadet" System, I'll show you first how to navigate there.
Go to the "Friends" section, it is beside the "Team List" and above the World Chat.
At the upper-right corner of the screen you will see "Friends" and "Sensei", tap or click the "Sensei" button.
Meet my Sensei! 
. Err- I mean back to the topic, now after you've navigated to this section, you will find 3 buttons below.
Those 3 buttons use is as follows:
Collab Missions - are missions that you will need to complete in order to receive bonus rewards (But I will explain the rest of that later).
Sensei Ranking - are for Captains that have already graduated and is now officially a Sensei, the more Cadets that does their Collab Missions under their Sensei, the more their Sensei gets credits and climbs up the ranks.
Application List - is where graduated Captains can apply to be your Sensei. If you've already graduated, this section will show you Captains that have applied to be your Cadet instead.
You might be wondering how to Graduate? It's actually simple! Let's now navigate to the Collab Missions Section.
The Collab Missions consists of 2 more sections. Examination Trial and Daily Teaching.
The Examination Trial consists of Trial Missions where you will need to complete in order to receive rewards, which benefits both you and your Sensei. But of course, if you're high level prior to becoming someone's Cadet, your Sensei will unfortunately receive minimal rewards. These are also the missions that you MUST complete in order to become a Sensei.
Daily Teaching consists of Daily Missions that you can complete with your Sensei, and some missions can be completed independently by the Cadet as well. Again, this benefits both you and your Sensei.
Here are the Total Rewards that can be received from Trial Missions from level 10 - level 70 (There are more rewards than this but I will only include the mainstream ones, you can discover the rest on your own):
- Crystals = 1,740
- Dorm Supply Cards = 8
- Coins = 1,140,000
- Asterites = 37,600
- EXP (Experience) = 3,900
Here's the link for the Part 2:
Honkai Impact 3: Sensei & Cadet System #2 - HoYoverse Player Community (hoyolab.com)
Note(s):
- In order to become a Sensei, you must graduate as a Cadet first.
- Sensei or Cadets are easier to find in the World Chat (So don't be shy to chat ok?).
- I will explain the "Sensei & Cadet System" #2 on my upcoming guides (That is of course, after I've graduated lol), but if someone has already made a guide for that please do check out theirs first to find the information you need.
