The general base rules are free now >>>>>> https://whc-cdn.games-workshop.com/wp-content/uploads/2017/06/Warhammer-40k-Battle-Primer-English.pdf
Literally 90% of the old rules are gone from the BRB, and if your units have any other rules it will be on their "Datasheet" (A Datasheet is the page/entry for the unit). So if you are suppose to get +1A on the charge it will say it on your units Datasheet.
New to Blogging, just starting https://maddpaint.blogspot.com/
AoS: BoC 9k, CoS 3k