Sure dude let me try correcting it.
First of all:
"Does it have something wrong?" (Does is used in interrogative form)
I have two sisters, they are called Andresa and Caroline. Andressa is Older(comparativo) than me and caroline is my young sister(baby sister sounds more "brotherish"). I'm the middle child (when you say middle brother seems as if you have a younger and older brother, not sisters). With a maximum diference of eight years between us, they are/seem( ou 1 ou outro não os 2)(seem =parece are= são) both small, (both) have curly hair, black eyes and a thin body. Both wear(have quer dizer que você tem, wear quer dizer que você usa) reading and writing glasses (Adjetivo especificando que tipo de óculos é)(Como não sei se existe diferença entre um óculos para ler outro para escrever vou deixar os 2 ali, mas acredito que botar óculos de leitura já seria o suficiente).
They are interested in ( When you are interested you are interested in something/someone) different things.("Their interests are completly different" fica melhor), for exAmple, my sister andresa likes(enjoys) watching novel and doing exercices but my sister Caroline likes(enjoys) reading and studying chemistry. Yes! She enjoys chemistry, she is studying chemestry at ETECAP in Campinas. Andressa is graduated in administration and works in a multinational company. Although they are different, they have something in common, they(both) love to buy clothes, I don't.
My sisters are funny but very temperamental. Bit by bit i'm learning(você esta aprendendo ou já aprendeu?) to stay out of their(do caminho delas) way when they want something. It (lembrar do pronome) isnt easy being the middle child, because i need to deal with the authority of my older sister and "the constant need of pampering from my"/"my pampered younger one".(pampering of my younger one = a sua irmã te mim)(se você queria usar a palavra mimo de mimada a palavra correta eh
Good text overall , nicely done. Here are some tips:
1) Just like portuguese every sentence needs a subject, which usually tend to be one of the pronouns
2) If you dont change the time of an action it remains at whatever time it was before (likes watching novel and doing)
3) Whenever you say that an object if for doing something remember, you can always put an adjetive before it( Reading glasses)
4) Remember the negative way to build a sentence ("I dont"/"he doesnt"/etc)
5) Although é um termo de oposição então ele só deve ser usado para ou contrapor uma ideia implicita anteriormente ou para "avisar que você vai fazer um contraste de ideias "como eu usei no texto.
Bom aprendizado e boa sorte!