Blogs: You have to enable multisite in your WP install first before you can let journalists create their own blogs. Read how to https://codex.wordpress.org/Create_A_Network
Template Pack: Here’s a BP Template Pack walkthrough which could shed some light on how to add styles – https://codex.buddypress.org/theme-development/bp-template-pack-walkthrough-level-easy-2/
Basically, you copy some styling from bp-default theme and tweak it to taste.
