To address the issue you seem to be having with paths, I suggest you read the documentation on them. To find documentation on any topic in GM, either go to Help -> Contents in GM itself and search for it there, or just do a web search for it and look at links from docs.yoyogames.com.
This page I found by searching "game maker path start." I think the path_start function on that page is what you're looking for. Learning how to effectively read documentation and web search is a good skill to have!
I've also reattached the project I made, converted to GM 8.