Hello Mayra, welcome to italki. I love cats, but unfortunately I can't have one in my small apartment. 

Introduction

Hi, 

My name is Mayra, I come from Colombia [you could also say, "I live in Colombia"]. This is my first entry. I would like learn English. I have a pet cat, its name is Akira. It is a cat.

Introduction

Hi

My name is Mayra. I am from / come from Colombia. This is my first entry. I would like to learn English. I have a pet, it's name is Akira. It is a cat. (Is it a girl or a boy? For a girl - Her name is Akira, she is a cat. For a boy - His name is Akira, he is a cat.) 

Hi Mayra! Well done on your first entry! I look forward to reading more :)

Introduction

Hi

My name is Mayra. I am from Colombia. This is my first entry. I would like to learn English. I have a pet its named is Akira. It is a cat. Or: "I have a cat named Akira." 

Introduction

Hi

My name is Mayra, I am from colombia. This is my first entry. I would like to learn English. I have a pet its name is Akira. It is a cat.

Well done, we use a capital letter for English, Spanish and French etc.