Is taking a seat in the Faculty of Medicine—benefiting from the law allocating 20% for military personnel's children—considered an injustice to others, especially since my GPA qualifies me for admission to another distant university, and what should I do after commencing my studies?

There is no objection to accepting the academic seat allocated for children of military personnel, so long as its acquisition was free from cheating or fraud. The state has designated this quota as a reward for military personnel, and the son is entitled to benefit from this seat and is not obligated to seek another one.