Do I have to connect the SG-1100 directly to my fiber port from the ISP or can I connect it to a port on the the router provided from my ISP?
I do not have a static IP provided by my ISP
If I connect the sg-1100 to my router and setup the wan as DHCP. Why can I not access the internet. I can ping the google DNS 8.8.8.8 but have not access to the internet to open a web site?
Does the isp router and the SG-1100 have to be on the same IP range?
If your provider doesn’t for whatever reason require you to use their router and you want to use pfSense as your main router, you should definitely connect pfSense directly to the modem so it gets a public IPv4 address (even if it’s not static) and an IPv6 prefix.
If you have another (consumer) router in between, that one will get the public IP and prefix. The WAN address of the pfSense router will consequently be in the range of the first router’s LAN network. This is called a double NAT. And unless the first router supports IPv6 prefix delegation, the local networks behind the pfSense will not be able to use IPv6 without NAT (and IPv6 with NAT is kinda dumb).
If you haven’t already since switching routers, try power cycling the modem. Some models will only hand out the public address to the first MAC address they learn after powering on.
After that, if the WAN interface is set to use DHCP, it should get a public IPv4 address. If it does, any further problems are likely on the pfSense configuration side. Set up DNS on pfSense via the GUI and then try to ping a host by domain name from the shell. If that works but you don’t have internet access from local networks, it’s definitely pfSense configuration that is the problem.