My question is should i create a linux from scratch or use a previous distribution, i know a LFS is going to be more customized but on the other hand, i can just edit debian or something, but LFS teaches you how linux works, i can't choose. I want to build a custom distro so bad, but i'm not sure what option to pick.

There both VERY different systems. You'll have to compile it from scratch on an existing distro (so make sure you have on installed) also it is time consuming so it might not be worth it. You also need to have quite a bit of linux experience under your belt first.

If you want to customize, most linux OS's let you do that right down to the core.