I've been using R on and off for about 4 years now, and I still find huge frustrations with trying to find the package to install for a particular function. Tonight's example is reversing scaling. I Google this, and get unscale - great! I read the documentation on unscale, and there's no mention of where the algae data comes from, NOR any mention of what package to install to get the unscale function. (Funny: I can scale, but I can't unscale - maybe someone didn't close the loop in their original package.) So ?? it, and get nothing that helps, and then I Google something like 'package for unscale', and still have to search to find ggfortify. Is there a better way? Please enlighten.
I googled "unscale R" and went to the first page:
https://www.rdocumentation.org/packages/DMwR/versions/0.4.1/topics/unscale
In the top right you can find "From:DMwR v0.4.1" this is the package to install and there you can find the reference of algae
https://www.rdocumentation.org/packages/DMwR/versions/0.4.1/topics/algae
Where are you reading the documentation? There should always be a way to trace it back to the package— that said, I obviously haven't read all R documentation from all possible sources.
As for a better way to find the package you want, I don't think there's one tried and true method. There are CRAN Task Views for broad categories.
When you say "a particular function" do you mean you literally know the name of the function, or you have an idea of what you want to be able to do? If it's a particular function that you've seen used somewhere, your best bet is to go to the source of wherever that somewhere is— it's definitely a best-practice to include your libraries/packages for reproducibilty, and there are clashing function names (they could be using a function from one package and you find the same function in another).