Hello! ^^ I want to tell you about myself)))

My name is Alena, I'm 16 years old,. I'm and a schoolgirl <em>(try to combine several phrases using conjunctions like 'and', 'but', 'so' ...)</em>. When I'll grow up I want to be a translator, so I'm going to study English for my work and career. My hobbies is are aquariums and dogs. I have a beautiful dog and a not so big aquarium with different fish. I have only studied English just in school.

<em>(paragraph)</em>

I'll be glad to speak with anyone all people =)) Add me!!!)))

Corrections in red.  Stylistics in blue.

Hello! ^^ I want to tell about me)))

My name is Alena. I'm 16 years old. I'm a schoolgirl. When I grow up, I want to be translator. I'm going to study English for my work and career. My hobbies are aquariums and dogs. I have a beautiful dog and not big aquarium with different fish. I studied English in school only. I'll glad to speak with all people [good alternative:  with everyone.] =)) Add me. )))

At age 16, your written English is already <em>very</em> good.  Congratulations to you.