Some question from a noob

1. I do not have the books yet, in the mean time where can I find information on the units, unit composition and loadouts?

2. What differentiates bretonian knights from empire knights, what differentiates the men at arms? In case I want to use proxies, what features would make it a bretonian knight and not an empire knight?

3. What is the best source to get up to speed on the new rules?

4. Into what is a first lore point I should start? ( video, black library book, wiki, etc)

Sorry if this does not fit the sub feel free to delete if this is not okay content