Complex sentence: After 1992 it became dangerous to live in Bosnia, because of the civil war, and so the 18 year old went to Serbia and signed for FK Kikinda, at that time a Serbian First League club.
Split into simpler sentences: After 1992 it became dangerous to live in Bosnia, because of the civil war, and so the 18 year old went to Serbia. He then moved on the FK Kikinda, at that time a Serbian First League club.