Hi @LeslieM and welcome. 
For security, it seems many CP users have gone with Shield Security as they have included ClassicPress support (even though the language is still decidedly “WP” in the dashboard). I know, the idea of configuring a new security plugin is no fun, but, at least it’s an option.
A couple of other resources to check out are the list of plugins confirmed working with CP 1.x and the list of plugins built specifically for ClassicPress.