You can run server with this command:
python server.py port_number
which port_number is a port like 8080 that your server listens into. it is by default hosted on your localhost but you can change it manually if you want to.
for running client you can start it with this command:
python server.py server_host_address server_port client_name
which server_host_address is actually localhost if you haven't changed it and server_port is the port_number you choosed for your server. client_name is your unique client name that others can see it in chatroom
after running client you see the guidance. so good luck!