Stop staying you are not naturally intelligent. You are naturally Intelligent. You have come here and raised a question to discover how to become a smarter person - this thought itself makes you smarter than your friend's circle.
Search for a thing that brings you inner emotion you are attached towards it. Admire it … Learn it. Become an expert and compete with yourself. You will be called a smarter guy in the next five years from now.
This is my humble answer to your humble and intelligent question.
Also, have a positive attitude, keep going never stop !!
Bring up the best version that is hidden in you. Nurture the good things that is residing in you.
Never say your are weaker to yourself. Just do it fail it and again do it in the same way , You be the master in it one day.
No term Intelligent is coined for a particular person to take up and own it.
Teach yourself and lean yourself to be the best.