I had some issues installing new java so here's a small guide!
- Go to this link and install the java 16 you want: https://adoptopenjdk.net/
They have a nice installation executable that auto sets your java home and other stuff.
- Copy what fabric example project did here: https://github.com/FabricMC/fabric-example-mod/commit/50f0be767c69f3ac49c3a2c4c8669354a39fd9b3
Remember to copy what the commit did for: build.gradle, fabric.mod.json, mixins.json, gradle-wrapper properties file, but update the gradle.properties with new versions from here: https://fabricmc.net/versions.html