Rek'sai? more Like no rek because no dmg pls help

Hello, i have bould the champion rek'sai and i have some some fun but sadly i go negative every game i play with her. It's very said see that she has been only nerfed and like her name is rek'sai so i think that she should be buffed so she can rek, so her name will be rek'and make you sad because i am fed and you are dead kinda like zed. i know i sound like a scrub and i suck at the game but i am new and i see people that do dmg with her and its because they have runes and since i am new, well not that new but i don't play like every day and i don't have access to full rune pages and stuff like that, so if you could link me to a guide or give me tips that would be very nice, and ap rek'sai q while burrowed that was cool so if you could bring that back that would be cool. ty rito.