Grab the "fresnel" node in ase, my dude. It literally is one node to make a simple fresnel effect. If you're using the dot product method then yes it will have more than one node and it gives you greater control over how the rim looks in the end but in general the "fresnel" node works just fine.
To chime in on whatever the fuck stupid thing is happening down below. Both of these guys use Amplify Shader Editor to create shaders. Using that asset you don't have to learn how to code anything to make a decent shader. And this fresnel effect? It's one node. You just drag and drop it in, modify some values, and you have a fresnel. Making it rainbow is another two or three nodes. You can make this effect in five SECONDS if you know what you're doing. Creating shaders is as easy as doing proofs in geometry class. You just need a logical mind to do it nowadays. People need to stop toting shaders up like they're the most difficult thing in the world to create.
It will work just fine but it's not ideal compared to using other shaders as there's not too many options besides the ones to control the effect itself.
Oh duplicate it and then rename it to a new file name then you can edit the shader path and it saves it just fine. Do this every time I wanna edit one of the samples