Please help we have no IT

Ok guys, I am in desperate need of assistance, and I don’t know where to begin. I recently took over as GM for a business. We don’t have any IT department/person and NO one in the company knows anything about our security system. We had some vandalism and theft, so we are trying to add some new cameras and access our system remotely. I am unable to access the DDNS or update the system. The security company we currently use said they are unable to get through or access the firewall. When I try to login using the IP address it says it is blacklisted. This is all outside of my range of knowledge, and I really don’t know where to get help, so any suggestions or assistance will be greatly appreciated.