Lab 5.8 issue VNC Server

I cannot get the vnc service to begin. I made the /etc/systemd/vncserver@.service file. Here is my file configuration:

Unit]
Description=Remote desktop service (VNC) on port :%I
After=syslog.target network.target

[Service]
Type=forking
User=justine

ExecStartPre=-/usr/bin/vncserver -kill :%i
ExecStart=/usr/bin/vncserver :%i -localhost
PIDFile=/home/student/.vnc/%H:%i.pid
ExecStop=-/usr/bin/vncserver -kill :%i

[Install]
WantedBy=multi-user.target

I changed ownership to justine using chown command.
sudo systemctl start vncserver42.service gives the "service not found " error

I must be missing something. Any help apppreciated