Test Automation on itself should not be a field if you ask me, therefor it is mostly software developers (that value automated testing highly) who write books/articles that drive the field. Because very good software developers are also very good testers.
My personal favorite is Kent Beck and his book Test-Driven Development.
Beck was one of ...
From the documentation I expect any "item" to be able to Convert To String: https://robotframework.org/robotframework/latest/libraries/BuiltIn.html#Convert%20To%20String
Maybe you should first Convert To Number, those seem Floats: https://robotframework.org/robotframework/latest/libraries/BuiltIn.html#Convert%20To%20Number
Get in contact with the developers. Just like with internal projects you probably need someone to guide you through the code to get started. Larger Open-Source projects often have a IRC channel or a mailing-list.
If you are really intressted in helping the project and not just to understand their test-architecture you could send a message to a communication ...
"A journey of a thousand miles begins with a single step"- Lao Tzu
Go Small .I would start with a known open source project- most likely an automation library which I am already using .
I would make a list of interesting API methods which I am using on daily basis and curious about how they work under the hood.
In this way I will take small baby steps to ...
Have a look at Alan Richardson who has a lot of online courses - mostly Java focussed and also useful for newbies (they are up-to-date and he provides coaching as well), books and is a general nice guy (not important in itself ;-) )
Another would be Richard Bradshaw who ticks the same boxes. Richard also provides several free online courses.
Both are ...
You can also wrap it in a function again to make it a bit more descriptive, and so you can include a sort of private methods.
prevent them ? hmmm
Educate on how to write them the right way
Educate on why to write them the right way
Dducate on consequences of writing poor ones
Have a review step before they are used
Create published standards
Agree to follow standards