The largest surviving group of Caldari roleplayers is I-RED, who are loyal to the Ishukone Corporation, and do stuff in both FW Lowsec and NPC null. Should you wish to get in touch with them, then @John_Revenent is your go-to.
There’s also a few smaller corporations floating around, but nothing that’s really publicly vocal, asides from perhaps @Thadius_Faran 's news agency.
Beyond that, the other vocal actor is @Diana_Kim who is loyal to Kaalakiota, and whose kokoro secretly goes doki doki for Heth.
Beyond that, there’s a discord server where Caldari roleplayers nominally frolic, but it is rather quiet:
Beyond that, there’s also the Roleplay Is Primary Discord, which has roleplayers from all factions, and is more active:
Of course, I also exist, but I mostly just hold my little trench in Faction Wars in silence, when my character isn’t on shoreleave.
If you would like to meet in-game other roleplayers, join in-game channel “Out of Character”.
If you would like to meet other characters and speak to them in-character, the best place to go is in-game channel “Intergalactic Summit”