How to create a 1.8.9 Client Clientsided?

[Mxrlin]

Even though it's basic knowledge to most of you (probably), I'm really stuck because I can't find any tutorials.
I want to code a 1.8.9 Client that is Clientsided, but I'm failing already at setupping the mod in my environment. I'm using IntelliJ but don't get it working with the Docs, as it is an Eclipse 1.18 Tutorial. The 1.8.9 MDK is outdated for IntelliJ (MDK is gradle V2, and IntelliJ requires Gradle V3). So how can I easily create a mod using IntelliJ? Are there any tutorials? If possible with IntelliJ but I could code with Eclipse too. But while downloading Eclipse, it said to have atleast a JDK 11, but Minecraft 1.8 is coded with the JDK 8 which would lead to errors I think.

[Curle]

The version you are using is no longer supported on this forum.

Please update to a modern version of Minecraft to receive support.

Currently supported versions are 1.18.1/1.18.2 (Latest) and 1.16.5 (LTS).