I am trying to work out how to say things from the vocabulary I have, not with much success....

Please could someone correct this?

Benim iki çocularim var.

Bir oğul, adı xxxxxx

Bir kız evlat,adı xxxxxxxxxx

´I have 2 children. 1 son, called xxxxxx, 1 daughter, called xxxxx

Is it çok kötu??

thanks

Iki çocuğum var

Bir oğulum var, ad xxxx

Bir kızım var, ad xxxx

(modified: I see Lady Red answered first.  What she writes is more correct)

This is my statement to buyukbalik 

bunu kötu değil! (This is is not bad!)

Not only not bad  I say its OK. (by that I mean basically, you would be understood)  "benim" may be unnecessary.   In the first line you added the personal suffix, but omitted later which LIR fixes.  

Thanks! I really struggle with the possessive endings......actually. I struggle with it all....

 You are not alone - believe me - you are not alone!!

Just to agree with LIR...

a mistake we English speakers often make is to put plural after we give a number.

In English we say one child, five childREN (with a plural ending on child)

In Turkish we say bir çocuk, beş çocuk (not çocuklar).

I still sometimes have a slip of the tongue on this one when speaking, even after 14 years!

PS... evlat is your child, but it is also used for to adopt (evlat edinmek).  So, not to avoid confusion, çocuğum is better than evladım

Thank you! you are all so kind and helpful!

 Bir oğlum var. The "u" drops there. There´s a rule about dropping vowels.