play semi carries, id suggest learning on corrupted desciple, he has a long range aoe spell that u dont have to target with, so its hard to fuck up + its great for farming.
ok, ive got a mind blank and cant remember my build, but what u want to do is, get 3 creeps low enough so that when u use your nuke, it gets 3 creep kills at once, only do it when youve got enough mana of course
dont auto attack, u probably know that
try to focus on where everyone is on the map, or where they should be.
and finally, why i suggest this hero, when youre in neutrals, you can shoot 1 of the monsters, and drag it close enough to another creep spawn that when you use your aoe spell, it hits 2 stacks, basically increases your gold per minute by killing 2 stacks quicker
apart from alst hitting like a pro & doing that, until you get to higher psr and supports start creep stacking (at :53 u hit creeps and run, and while they arent in the spawn, the next wave of them spawn. there will now be 2 stacks of neuts.
all u need to know now is how to farm well, and try to only play heroes you KNOW the role of. there is initiators, gankers, support, semi carry and carry
unless you know the heroes role, dont pick it.
apart from that all u can do is practice