Always opt for an i7 with at LEAST 8GB of ram and these days an SSD is basically essential.
As far as a gaming laptop - it's a bitter sweet because you either want a laptop to game or you want a laptop for school.
A laptop for school should be lightweight so you can carry it everywhere with little hassle, which means as big as 14'' screen, no CD drive and no dedicated card. A dedicated card will add weight to the laptop, even 1lb makes a difference.
But an i7, 8GB ram, 500GB SSD laptop with intel graphics should be more than enough for older games.
Dell XPS 13 may be the way to go for you or the New Inspiron 14 5000 with GeForce MX250
Otherwise you're looking for XPS 15 with GTX 1050TI or ALienware m15 with GTX1060 (not as light but better than 6+lbs)