This popular SourceMod plugin allows you to play custom music or CS:GO music kits at the end of rounds.
For specific sound effects (SFX), sites like Pixabay provide royalty-free CS:GO weapon and voice clips. skachat zvuki iz cs go dlia css
CSGO: как сделать звуки шагов громче | гайд - click-storm.ru This popular SourceMod plugin allows you to play
If you run a CSS server and want all players to hear CS:GO sounds, you can use specialized plugins: skachat zvuki iz cs go dlia css
This blog post outlines how to modernise your Counter-Strike: Source (CSS) experience by importing high-fidelity sounds from CS:GO (now CS2).