That is literally how you would say "I'm lucky" in Brazilian Portuguese: eu estou com sorte.
estar com (beginner)
In Brazilian Portuguese it's important to remember that this special combination of ESTAR + COM is used to say things like:
I'm thirsty. > Eu estou com sede.
I'm cold. > Eu estou com frio.
And of course this works when talking about other people as well:
He's jealous. > Ele está com ciúmes.
Are you feverish? > Você está com febre?
But you can't use this to say things like I'm happy, She's sad ETC. And there's no real reason why! It's just that there is a specific set of accepted ways to use ESTAR COM. The good news is that you can learn 90% of them right now. If you learn the examples above and these below you'll already know the most common uses.
He's got money. > Ele está com dinheiro.
I'm in a hurry. > Eu estou com pressa.
Do you have problems? > Você está com problemas?
All of this works in the negative as well:
He's out of money. > Ele está sem dinheiro.
I'm out of time. > Eu estou sem tempo.
If you can remember these, you'll be speaking like a Brazilian!
Some more complex examples:
You can of course express these things without the estar + com/sem combo. If you can do that, you are really doing well with your studies. And you can even say for example, Eu tenho fome. -- But it's not what Brazilian's say. Don't be afraid to be inventive and creative with the language. But take the time to know the most common ways to say things first. Your mistakes will go over much better when mixed-in with correct, standard speech.
Brazilians will actually use the ESTAR COM combo to express: to have. Like this:
Ele está com muito trabalho. > He has a lot of work.
Ela está com um vestido bonito. > She has a pretty dress.
Estamos sem nada para fazer. > We don't have anything to do.
Have you heard other examples? Leave it in the comments below!
Look at this example in-context. Here, Amanda is saying that she/they are behind (atrasada) on the rent. Brazilians would literally say, that you are "with a late account".
Você não pagou o aluguel?
Eu paguei Dezembro. Mas Janeiro e Fevereiro estão em aberto.
Você está com a conta atrasada, então.
Não. Estamos com a conta atrasada.
Com tom de indignação ela diz,
De dois meses, é isso?
estar de (intermediate)
Another VERY useful (and common) combination with estar is, ESTAR + DE. This has always confused me a bit as there seems to be overlap with estar com. Here are the really common ways that Brazilians use estar de:
Estou de dieta. > I'm on a diet.
Ela está de vestido. > She's wearing a dress.
Você está de mal humor? > Are you in a bad mood?
Don't worry about mixing these up. If you say "eu estou de febre" - that's fine. It works. Brazilians will even say it that way. Just read the examples above and take the quiz below to get familiarized with the core usages here.
For a better look at the different ways you can use ESTAR, read this post.