Hello my name is dDilara.

Hello, Dilara! Welcome! I'm going to correct your capitalization, but I know that sometimes it's less important in informal texts like this.

I am from tTurkey.

I am twenty -three years old, I was born in sSivas.

When we write out compound numbers, we usually use a hyphen (-) between the different parts.

I am studıedying at aAnkara uUniversity.

"I am studying" because it is happening in the present.

mMy department ıis radiotherapy.

itIt's a hard department but iI like ithem.

Tricky sentence!

It's a hard department --> The word "it's" needs an apostrophe (') because it's a contraction of two words - it and is. "Its" is also a word, but it means "belongs to it" so it's important to differentiate.

I like it --> "them" would refer to something plural. The department is singular, so we use the singular "it" instead. Maybe you wanted to say something like "The professors in the department are difficult, but I like them" or maybe "The classes in the department are challenging, but I like them" instead?

I am unemployed.

Perfect sentence!

I live in aAnkara.