Help im a vtuber and getting a new custom pc but don’t know what parts to get budget negotiable

I’m sorry in advance for my grammar

my current pc is my brothers old custom build from 9 years ago only 1 fan works and usually turns on if in right position help

motherboard : MSI Z370 GAMING PLUS (MS-7B61)

CPU :intel Core i5-8400

GPU :NVIDIA GeForce GTX 1070 Ti 8 GB

RAM: 16.0 GB

easily gets up to 80 degrees gaming