Now I'm 3years old I've grown up a little bit more expanded my knowledge and chakra capacity trained a few hand seals learned some basic water and earth Jutsu like Doton: Rock Trow technique and Suiton: Seal Creator the last one make me able to manipulate my ink when I'm drawing a seal etc nothing combat-ready but very useful Jutsus.
Dad: Aizen come here, let's have breakfast and start your shinobi training.
Aizen: Coming dad.
Yes, my name is Senju Aizen quite a good name if I do say myself. After finishing breakfast I follow my after to one of the Senju training grounds an open space in the middle of one of our forests pretty good place to train.
Dad: Now son that you're 3 years old we can start your shinobi training, first and foremost for me to prepare some Jutsus for you to learn take this paper and inject your chakra into it.
Dad: Hmm Doton and Suiton good, pretty common for a Senju but both are good affinities.
Dad: You're also a sensor so we should train that, but we should start with our Senju style Taijutsu The Bark Breaking Fist it consists of strong kicks and fists using your superior strength and weight often breaking the place where you land your attacks. (this style is similar to Tsunade own fighting style and close combat techniques come from here).
Dad: There are currently 26 katas of the Bark Breaking fist today we will train the initial 3. observe.
And then my father demonstrated the katas and I repeated it, so after I was relatively good with the katas I practice chakra control and other physical exercises and quickly the day comes to an end but a quick cycle of Mokuton chakra and most of my muscle fatigue is gone, heaven this chakra is simply too good at healing.
The next morning my father said he created a library with all the essential books and some Jutsu that he will update from time to time.
Having the green card to train I started straight away first training my body them chakra control then taijutsu and going to ''sleep'', I only really sleep on Sundays most of my nights are spent on deep meditation.
After some time I started training the academy Three, I did train them until I'm a master of them, for example, seales substitution, being able to move Bunshin precisely, ''perfect'' transformation Jutsu like being able to transform into Kunais and big rodents, even picked up Shunshin but am not a master at it yet, I'm practicing it a lot because if my theory is right with observation Haki I should be able to bypass its weakness, I too practice with some basic water and earth Jutsus just to get at least an initial feel for the element. I decided to make my Mokuton a secret until the third ninja war there I will literally paint a target on my back, yep that's the major problem with Mokuton just being a Senju already make me a target imagine if show Mokuton, thanks to Hashirama everyone keeps assassinating the Senjus just to diminish the chances of a Mokuton user appearing.
On the physical part, I started training trowing weapons and having quite a decent progress there, I seriously trained the katas to integrate them on my muscle memory, on the plus side I learned Doton: Rock Fist with it I can encase my hands and even other parts of the body with a lot of practice but the thing that made this Jutsu essential is the fact that I can increase its weight making my physical training even better, the only technique that would be better to train is the Doton: Added weight Rock technique but I would need to invade Iwa archives for it.