My apartment

I live in an apartment in Belo Horizonte. It isn’t a new apartment, but isn’t an old apartment either. I’m not sure, but I think it was built 10 years ago. It’s a good apartment. There are three bedrooms. One we use as an office and another ('the other' if it's the ONLY other) as a visitor's room (Or 'a room for visitors'. I think that's what you mean, right?). The third is my bedroom. In my apartment there are also two bathrooms, a living room and a kitchen. Next to the kitchen there is a “service area”, where there is a washing machine. In front of my living room there is a balcony with some plants. It’s a good place to relax.
I live with my husband and my two little cats. But often our friends and parents visit us. They sleep in the visitor's room (Actually, I think you mean what we normally call 'a guest room', so they sleep in the guest room.).
I like my apartment because it’s next to my work and to my husband’s work. In addition, there are some restaurants, supermarkets, banks and other services next to it.

This is generally well written.  It seems like you have a nice apartment.

My apartment

I live in an apartment in Belo Horizonte. It isn't a new apartment, but it isn't old either. I'm not sure, but I think it was built 10 years ago. It's a good apartment. There are three bedrooms. We use one of them as an office and the other as a guest room. The third is my bedroom. In my apartment there are two bathrooms, a living room and a kitchen. Next to the kitchen, there is a “laudry area”, where there is a washing machine. In front of my living room, there is a balcony with some plants. It's a good place to relax.
I live with my husband and my two small cats. But usually our friends and parents visit us. They sleep in the guest room.
I like my apartment because it's next to my work and to my husband's work. In addition, there are some restaurants, supermarkets, banks and other services next to it.

Good job, Ana! :)