I am a complete amateur at this. How would I get this AppleScript to work on my Macbook Pro on boot? What steps do I need to take? What does the script do?
If you want it to launch at login (which I don't recommend, and I'll explain why), add it to your login options. To do this, open System Preferences -> Users and Groups. Select your name in the sidebar, then select Login Items in the main pane.
Next, hit the + button and navigate to wherever you have TardisGlow and hit add.
Now it will launch whenever you login.
However, I'm not sure I would recommend this, for one simple reason: the way the script works (though completely harmless) is by dimming and raising the backlight, which will be extremely distracting if you want to use your computer. Admittedly, as configured, it only runs for 7.2 seconds before resetting it to normal (after playing some sounds)–but if you want to keep running that effect, it will need to keep running.
If, however, you decide that you do want to have it continually run, you'll need to change the line
repeat 4.5 times to
repeat in the script. To do so, go to the app, right click it, and hit show package contents. Next, navigate to Contents/Resources/Scripts/main.scpt and open it. Then, change the line as noted before and save.