Yarýn uzun yolculuðý Turkiye´ye baþlacakum.

Bu doðru mu?

 ..........baþlayacaðým.

 not sure if sentence is correct , but looks ok to me , although i am also only a learner however i see one small  mistake

If you are using baþlacakum (baþlamak)  it must be baþlayacaðým ..( In relation to vowel harmony )  I will commmence/ begin

Slow slow, always so slow lol

My try:

Yarýn Türkiye´ye uzun bir yolculuða baþlayacaðým.

baþlamak requires its object to have the -a/e ending

(Learner, corrections may be needed)

grammatical aspect:

Yarýn Türkiye´ye doðru uzun bir yolculuða çýkacaðým.

Thank you Seyit for the correction.  

 Hasn´t that changed the meaning from my original sentence???

"Tommorrow I start the long journey to Turkia"

open for discussion:

discussion period expired

Result:   I think it is exactly same what you said in English.