The resolution is set to 1980x1020 so you will need the screen to be that or greater.
A Raspberry Pi 1 is not fast enough to draw this clock every second, better to to use a Raspberry Pi 2 or 3.
To stop the screen from blanking you can install xscreensaver.
Open LXTerminal and enter the following line:
sudo apt-get install xscreensaver
Reboot. Then and click on start, preferences, screensaver and set the mode to "Disable Screen Saver"
To draw antialiased lines Pygame requires the colour depth to be either 24 or 32 bits. To set this you'll need to edit the file /boot/config.txt
You can do this from LXTerminal. Enter:
cd /boot
then:
sudo nano config.txt
add the line:
framebuffer_depth=24
Do not put spaces either side of the equals sign. And save the file (press ctrl+o)
To get the file to autostart:
Open filemanager and go to /home/pi/.config/ (you'll have to type in the .config bit as it's a hidden folder)
Then make a folder called "autostart" In autostart make a new file and call it "Clock.desktop" Edit this file and enter the following text:
[Desktop Entry]
Name=Clock
Exec=gksu python /home/pi/Desktop/Clock.pyw
StartupNotify=false
Terminal=false
Type=Application
Save the file.
Also you'll need to edit Clock.pwy again and comment out line 65 and uncomment line 67.
If you've saved Clock.pyw and logo.png anywhere other than /home/pi/Desktop then you'll need to edit line 67 otherwise it won't be able to find the image.