New player advice

Hi guys this is my first league and i really really love the game so far , i managed to get voidstones all 4 of them after 3 month lol , but i had fun.
i am using Ls slayer with svalin but i feel quite lost on how to improve my build

here is my pob

Level 93 Crit Vaal Lightning Strike Slayer [3.25] (pobb.in)

i managed to farm around 20div and if i grind hard this weekend i can make em 50div

i have 2 questions

with this budget how can i improve my build?

i am also thinking about respecing to flickr striker cause it looks so cool can you recommend me a build with the same budget 40 to 50 div

i tried searching but i felt really lost there is so many options