Iris Mod – Allows for use of Sodium and shaders, creates new menu overlay.
Sodium Mod – Custom Rendering Engine
Poshper – custom Lighting rendering
These can all be added to your client using Fabric. I use MultiMC which is relatively easy to add Fabric to. If you use some other launcher the first place to google is “adding Fabric to Minecraft”. From there you just need to add each of the mods to your mods folder (found in your minecraft folder).
https://irisshaders.net/download (this has a universal installer – probably best choice if you have vanilla MC launcher), if you do NOT use the vanilla launcher, locate the download for each individual mod (I have listed the ones I used below)
https://www.curseforge.com/minecraft/mc-mods/phosphor
These are the versions I used with MultiMC and Fabric Loader 0.13.3: