I actually love simplifying rap lyrics, so let me try.

He’s literally saying:

I am a gangster, I can walk anywhere I choose *
Any block I choose, I can walk
down any street, wherever

Lmao

* I just want to add that there IS a decent amount of meaning behind (at least) two specific words.

“Stepper” is someone who is violent, probably carries a gun, and isn’t afraid of prison.

Him saying “G-Block” is stating that he is and represents gangsterdom.