EDIT: Oh my gosh never mind I fixed it! All I had to do was delete an incomplete *sm_init I had in my startup file a few lines below the completed version, and it booted up just fine! And I’ve tested the load/save features and it all works perfect! 
I guess I forgot to delete it from when I was messing with the placement order in relation to all the *creates and stuff!
Okay so I got the SMPlugin.js and SMPluginMenuAddon.js, and I put them in the proper folders and I used notepad++ to open SMPlugin and put my gameid into it, and I also put sm_init into my startup.txt, as well as wrote the proper script direct things into the INDEX file, so that’s all good. But what isn’t good is I’m getting an error now that says:
“SaveMod: Non existent game_id argument for *init_savemod!”
I don’t know what this even is or where to go to even fix it! Please help? Did I have to put *init_savemod into my startup file too, like under sm_init or what?