maybe the versions of menyoo and script hook are not compatible with gta 5, before installing any mod check the requirements of it.

in order to create a mod, you have to be expert in some good scripting language, as you are beginner try to learn from tutorials then start to make one.

I would suggest a faster Hard Drive. I'm not sure what you're running but I just installed mine onto an SSHD and everything is better. It doesn't help FPS but loading times are cut in half and textures loading in late or glitching around are gone.

One thing the guide doesn't really mention I mean sort of in passing but not in depth is how to install mods using the RAGE. I know the RAGE has a plugins folder and you drag .dll files, but for some mods (Addon Car Spawner) dragging the .dll, the .ini, and the folder into the plugins folder simply doesn't work. Perhaps the guide could elaborate on what RAGE is good.

Yes it does load vanilla without any replaced cars. The mods folder seems to have all the right folder's/files.
I just need to have the rpf files in the mods folder right? i don't need to put them in another folder or something?