My ISP provided modem/router combo (Home Hub 3000 from Bell Canada) does not have a firewall setting, is this an issue for all of the devices on my network? Or is the router doing some packet filtering or something along those lines without me knowing? If anyone has this or any other Bell modem/router and is knowledgeable about the topic that would be greatly appreciated.
A router does NAT and that means no incoming connections being made from the internet to your public IP will ever reach the machines inside your network. They'll simply be dropped / ignored. Only if a machine initiates a connection then a response from some server on the internet will be forwarded to it. Because of this NAT is in itself a very solid firewall that protect your computers against threats coming from the internet.
https://whatismyipaddress.com/nat