So I'm not into the pokemon meta and I'm trying to add EV's for my Weedle on the stat calculator, but it won't let me add more than 510 total EV points.  I know the max value is 255, so which two stats do I apply the EV to? Is it my choice? Is there a 'best choice' given my final Evo is Beedrill? Do I split 510 evenly among all six stats?

Help! I'm just a dumb pokemon in need of trainer guidance!