Complex sentence: Afghanistan started its FIFA World Cup campaign for the first time in 2003 while they played Turkmenistan in 2006 FIFA World Cup qualification which they lost both matches in aggregate of 13--0.
Split into simpler sentences: Afghanistan started its FIFA World Cup campaign for the first time in 2003 where they played Turkmenistan in 2006 FIFA World Cup qualification. They lost both matches in aggregate of 13--0.