From an RP point of view
1 tomoe Sharingan
The user will need to experience a terrifying, stressful and life threatening situation to awaken his sharingan, which will automatically awaken as a 1 Tomoe sharingan. The user will then have to pass through a training session with a certified sensei that helped him awake it.
This type of Sharingan has 1 tomoe surrounding the users pupil and is gained at the moment of awakening the Sharingan. It allows the user to perceive motions and see chakra. The user's pupil turns bloody red, and gains an extra pupil, or tomoe within each eye that will surround the original, centered pupil. When active the user now has the ability to track speeds that would only be seen by a higher ranked, more experienced ninja. They also gain the ability to see through visual D rank genjutsu (visual illusions) and can follow the movement of most taijutsu moves done by normal Shinobi, even those faster than the user and the movement of most Ninjutsu, allowing one to be able to react best to the situation. To activate it the user will spend a move of his 3 per turn while he can keep it active throughout the match as long as he has chakra to fuel it.
2 tomoe Sharingan
Must have 1 Tomoe sharingan and gone through the first training session. At that point, the user will need to go through a 2nd training session to further hone his skills and abilities.
It allows the user to perceive motions as well as be able to copy the motions perceived as long as he is able to perform them physically. When activated the user's eyes turn blood red, and gain two extra pupils, the tomoe which surrounds the original pupil. At this level the user gains a better understanding of the sharingan. The user can now anticipate and analyze faster movement, as well as mimic minor movements made by an opponent. The user can now track higher speeds (almost twice as fast) and, by reading the handseals, can predict to some extent the use of Ninjutsu techniques (but will always obey and abide by the time frame rule as he can never start performing a counter/move before the opponent has started his, meaning that there will always be a logical sequence of moves that will obey the time frame). The user is now able to pierce through visual C rank genjutsu and below. To activate it the user will spend a move of his 3 per turn while he can keep it active throughout the match as long as he has chakra to fuel it.
3 tomoe Sharingan
Must have 2 Tomoe sharingan and gone through the second training session. At that point, the user will need to go through a 3rd training session to further hone his skills and abilities.
This is type of Sharingan has 3 tomoe. It allows the user to perceive motions, copy the motions perceived, and predict motions. An example of this is during the fight between Sasuke and Naruto at the Valley of the End. Sasuke could perceive Naruto's motions, copy them, and than predict what Naruto was going to do next. Essentially, to Sasuke through use of his Sharingan, it looked like Naruto was going in slow motion. When active the user now has the ability to keep up with extremely high speeds and mimic basic taijutsu exactly. With this the user can now copy handseals done by an opponent (using the adequate Copy Technique), and use jutsus as they do as long as he's able to perform them (having the adequate chakra nature, adequate knowledge of the field of expertise being copied, etc). The user must however be able to mimic the techniques, for if they are not physically able to preform the copied techniques they cannot do them. The user can now pierce through visual B rank genjutsu and below. Unlike the previous two sharingan stages this level has the ability to hypnotize a target. If however the target is too strong the hypnotizing with be ineffective. This can only be done on targets one rank below the user and through eye contact. The user will need to spend a move to activate it and will be able to keep it active until the end of the match as long as he has chakra and stamina for it. However, after some time, he'll be able to gain full mastery over the KG and gain the ability to activate it passively wiithout spending a move. He'll need to be Sanin Rank and have gained 3T for one month.