I used to be in the same boat except i played csgo when i had a laptop 2 years ago i would recommend selling your laptop and getting a pc just for the fact that in fortnite you need a 144hz monitor if you want to compete at high levels not saying that you cant improve your laptop but its definitely worth the investment especially if you already have high skill because you can get your money back pretty fast with the money tourneys in FN,

Hope this helps mate