In which direction to move when setting up the network?

Question

linux

Hello. There was a question on adjustment of a local area network.
Available:

• switch TL-SG1008D
  
• wifi router TL-RW940n
  
• 4g internet via router B593s-601
  
• desktop as a server with freshly installed Ubuntu on board
  
• 5 PCs in LAN
  

What you need:
- Internet speed control (wifi)
- file server
- print server
- firewall
The task is to pass Internet traffic through the server in order to control and kill the speed on computers and wifi, while wifi should not be visible computers on the local network. The problem is that there is only one network card on the server, and the modem is also connected via RJ45. Plus, I have not worked with Ubuntu before, I only configured Apache, Nginx, MDP on hostings with Centos.
I would be very grateful for a kick in the right direction.

Answer 1

Buy one more network card for the server.
"Router" connect to the server in bridge mode.
Connect the modem to the server.
Office lokalku-there.
Instead of finishing from Ubuntu, install a ready-made distribution kit for the edge computer. pfSense as an option.
Read "Computer Networks" by Tannenbaum, so as not to run to the store for TCP packets.