How to set up ethernet ports in house

This may be a noob question   , but here it goes... Ok, so my house has 4 ports in each room, 2 coaxial, 1 for the net, and one for a TV, and there's a phone jack and a Cat5e Ethernet port. From what I have learned, all my ports lead up to a "closet", and I have found it. It has all the connections for the LAN, and everything else. I am confused on what to do next. I see that there are blue Ethernet cords connected to the ports on one side, and that they are not connected to anything on the other. I thought I had to buy a switch for all these ports, and I haven't done so yet.

My question is, where am I supposed to connect the modem to the internet. It is currently connected to the internet coaxial port, which it then connect to the VoIP switch, and is then connected to everything else. Where is the coaxial port that I have to plug it in to, and what is it labeled? Also, once I get a switch, is there a specific port where I plug in my Ethernet cord into? I'll upload a picture tomorrow hopefully.

I'm am such a noob...