Note: I know, this is not new info, but I thought it would be good to post this so other n00bs like myself looking for help can find it easier than I did.
I've been struggling to get AVISynth+ working on it's own. In looking around for help, I came across this Doom9 thread about
StaxRip
It is basically a GUI for AVISynth+ (or Vaporsynth), like the more popular MeGUI or Avanti, but has much more versatility. I don't know all of the available AVISynth commands to just type out a script off the top of my head in AvsPmod, but this has them all listed in menus so you can see what is available. Makes starting out not quite so intimidating and decreases the learning curve slope significantly. You can also edit the code directly once you get more comfortable with it. I only use a few commands for noise reduction and QTGMC, but there are many others to try.
There is one bug I found while trying multi-threading- the program uses the old AVISynth "SetMTMode" command instead of the AVISynth+ command "SetFilterMTMode". Edit the code and add the "Filter" and correct parameters. Done.
It also works fine in Windows 10x64, so those of us with newer computers can use it.
Once you are comfortable with StaxRip, it is easier to move on to AvsPmod or other script editors.