I learned to script by messing around with an SVD's script, trying to make it have a longer reload time, but ended up making it shoot through everything, and tried editing the script again to fix that, messed up, tried fixing that, and so on.. Then tried editing other weapons and items' scripts, failing and re-trying. That was about 1.4 years ago.
The best way to learn basic BL add-on scripting is by trial and error, re-trying, and having the time to do it.