Bro, before anything else, you need to learn the basics of any 3D software of your choice. Zmodeler comes with the ease of its simplicity and it's the ideal tool for beginners in modding. So, I would go with Zmodeler for a start. Once you master the basics (move things around, scale things up and down and etc) in Zmodeler you can jump to MW modding.
AJ has a lot of stuff posted in his blog I still use to this date:
https://nfsmodderscorner.blogspot.com/2021/02/nfsmw-general-modding-information-old.html
AJ has a lot of stuff posted in his blog I still use to this date:
https://nfsmodderscorner.blogspot.com/2021/02/nfsmw-general-modding-information-old.html