im completely lost

so. i just saw book of the dead in a yt video and wanted to try it out, i've gotten so far as to import from the asset store but dont know what to do now, i tried to find guides to no avail and what i did find i didnt understand, dont know if it helps but im a pretty hardcore modder (not making mod) and know my way around alot of tech but this is a whole other level so just wanted to ask what to do or how to "load?" i guess book of the dead

 

https://forum.unity.com/threads/book-of-the-dead-environment.536902/

 

Copy the Masters,
start small,
take it one piece at a time,
do the Unity Tutorials,
don't give up, never surrender.