Your efforts appear to be focused on education.
A good technique might be to present Hive as a platform for learning about cryptocurrency and monetary systems.
Do you have a web site?
It is usually considered bad form to use a social network platform to promote another. I believe that Facebook has a history of acting against groups that they feel are promoting financial schemes. They would probably classify Hive as a financial scheme.
If you have a personal site; then you can load the personal web site with the onboarding information.
PS: Do you know any of your followers personally? I think the easiest way to onboard people is with face to face direct communication.