Although the spelling of أنا ('ana) indicates a long ا (aa) sound. It is always pronounced ('ana), The use of (anaa) has a special usage (particularly found in the reciting of sacred religious texts (i.e. the Quran). So just say ('a-na). That's the Arabic word for "I". "I" and أنا are the singular, first person, nominative pronoun.

أنا ولد

'ana walad(un)
I am a boy.(I'm a boy)

أنا ولد والكتاب كبير

'ana waladun wa_al_kitaabu kabiir(un)
I am a boy and the book is big.

أنا بنت والكتاب كبير جدا

'ana bintun wa_al_kitaabu kabiirun jiddan
I'm a girl and the book is very big.

أنا من كندا

'ana min kanada
I'm from Canada.

أنا من لبنان

'ana min lubnaan
I'm from Lebanon.

أنا ولد من العاصمة

'ana waladun min al-`aaSimah(-ti)
I am a boy from the capital.

أنا ذهبت إلى الـمدرسة

'ana dhahabtu ila al_madrasah(-ti)
I went to school.