Is there any guide on how to use this? First time using LTN and I cannot wrap my head around how this is supposed to be setup and cannot find anything online that is helpful with modernized. Even just a BP I could reference would work.

The real magic in LTN. LTN is configurable via signals input to the LTN stops. Without this mod you use a standard constant combinator. This mod makes the UI for the combinator LTN specific, otherwise it functions the same as a constant combinator.

A link to a full maual on how to use LTN and control it via signals is available at the https://mods.factorio.com/mod/LogisticTrainNetwork Mod.

I have added tool tips to each of the signals which should help a bit with understanding their purpose. There is a full manual for LTN in general, and I have added a link on this mods Information tab.