Security on VPS @

PBX Firmware: 3.211.63-10
PBX Service Pack:

I’m pretty inexperienced with FreePBX so forgive me if I sound like an idiot. I’m also don’t have a clue what I’m doing when it comes to linux (but am willing to learn what I need to). That said I just signed up over at for a vps. They were very unclear about security and all they would say is they had fail2ban setup. Seeing that it’s hosted I want to make sure that it’s secure and I don’t open myself up to a $10,000 mistake because it gets hacked.
Should I be concerned about doing something additional to secure the server? If so is there documentation somewhere on what I should do (I’m stupid when it comes to linux)? I love what I’ve seen with FreePBX so far, but don’t want to go the cheap route if I need to hire someone to do it right. Thank you in advance.