Joining two different IP-Class LANs

Good day guys.

I have no option but to come to you for your advice.

First of all, day day guys, my name is Casper and I am from South Africa.

I have a bit of a issue with combining two LANs, 0ne a c-class and the other a a-class. Now, I am no Mikrotik guru nor expert, but can do the basic stuff. However, this is a bit complicated. Let me explain.

I have existing LAN. I also have a newly installed Fibre LAN that has been unused. However, my company is terminating their contract with our existing tele-communication company and therefor, I now need to use the Fibre connection which is managed by a 3rd part. So, please keep in mind that anything on the Fibre LAN I cannot configure nor change. The Firbe company gave me 1 port on their switch, and 1 IP only. However, the DHCP is running on their router.

I will post a pic of the issue below.

The thing is now, I have it running, but there are a lot of issues like if I connect to Wifi, I cannot ping the 192.0.0.0 Lan except if I give the Wifi NIC a manual IP. I need help with how to setup the DHCP server, or then a replay, which for some reason I cant get right. My internet is now going to be on the Firbe LAN, and my network on my existing LAN.

Do I need to use Bridging?
Do I need to assign a IP to the bridge? If yes, On which IP set? And, is this IP different to the IP I assigned to Ether2? Hell, do I even need to give ether2 a IP

Please PLEAAAASE help me to get this LAN merged in a detailed reply, as if I know nothing please guys. Also, do I need to add masquerading on firewall? How do I setup DHCP, and on which IP, or must I relay the DHCP Server of the 10.0.0.0 LAN?

I want to be able to connect to the WiFi, Use the 10.0.0.0 Internet, and access the 192.0.0.0 servers and printers.

Please note that the AP i use is NOT a Mikrotik.