Two weeks passed since that fateful day and I worked hard like my life was dependent on it which it was. Let me tell you what happened, I brought my body to peak in just two weeks using potions that were found at my house in statis. They work like magic (no pun intended). The news on my escape was finally out and the magical world was in disarray. I haven't ventured into the magical world because I am afraid of being recognized and I don't want to ruin the life I got so soon.
I also relearned till the NEWTs level in Transfiguration, Charms, Potions, and Curses and reinforced my control over Occlumency shields (yes you heard it correctly, I have multiple shields over my mind) and also managed to learn a little bit of Legilimency from its basic and trying it on muggles (nothing over the top like forcefully invading their mind just overlook of their thoughts) because I thought learning it would be useful in the long road.
I also had Kreature access the Black vaults in Gringotts by giving him very specific instructions so he could not betray me. So, I had gold and access to the black library, I went full-on Hermione mode and learn as much as I can mainly in curses and transfiguration because they were my (Sirius) favorite subjects.
I learned to use my environment in duels using transfiguration but I am only at basics in it as Sirius never worked hard on it, he just focused on curses that can be fired instantaneously which I learned much faster.
After two weeks I pondered on the situation that was before me, what should I do for the next year? One way was to change everything and set the future on a new path, another way was to keep the timeline the same and change nothing and the third way was to change a few minute things that can help me later.
So naturally, I went for the third way and decided to keep the timeline the same till the end of the fourth year
(Explanation: I will have to let wormtail escape so he can resurrect Voldemort with Harry's blood because of the Horcrux inside his head.)
Soon 6th of August came and it was the day when Harry inflated Marge and saw Sirius for the first time and I want to keep it the same way. When I reached No. 4 Privet Drive harry was already leaving the house and then he saw me in my grim dog form. He fell when the knight bus came and the rest continues the same as in the books. He will spend all his time in Diagon Alley till the 1st of September and I can prepare my confrontation with him and moony at the end of his year. If this goes wrong even a single bit, I could be considered guilty and rotting in Azkaban till the end of my life or worse soulless before the next year so I have to plan it minute by minute.
Soon it was October 31st and I was in the forbidden forest planning to try and fail to break into Gryffindor's common room. As the feast started, I went to the cellar of honey dukes and went to the secret passage leading me to the one-eyed witch statue by the stairs of the DADA classroom. Luckily moony was at the great hall for the feast. I went to Gryffindor tower and to the entrance of the common room which was the portrait of the fat lady. As soon as I reached there, I transformed into my human form and went to the portrait she noticed me and starts screaming, I immediately silenced her and threaten her to let me enter the common room and started acting like a lunatic, I also slashed her and she fled her frame. When she did that I went to the corridor where there are no portraits and transform into a dog and went to the forbidden forest and apparated as soon as I reached the boundary. Today was a success. Now I have to start befriending Crookshanks and most of my time will be divided between staying at Grimmauld place and here at the forbidden forest.