Would 'Eu estou na minha casa' be correct as well ?
What about "Eu sou na minha casa"? Why is that wrong?
We always use "estar in/at/on some place".
Unless you never leave...
Is it possible to say "Eu sou do minha casa"?
No, that's not correct.
Does saying "fico em casa" work as well? I know it basically means "i am at home"...
Ficar em casa is used the same way as "to stay home" in English...=)
em casa indicates "my house"