You can delete the lock file with the following command:

sudo rm /var/lib/apt/lists/lock

sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock

How to add fonts in ubuntu:

1. Upload/ssh the font(s) to your home folder on the server

2. Copy font to the system fonts folder, this way it can be used by all users on the system 
    sudo cp -R ~/trade-gothic /usr/share/fonts/truetype/

3. Check permissions sudo chmod 755 /usr/share/fonts/truetype/trade-gothic/

4. Install the fonts so applications can use them sudo fc-cache -f -v