The number of packages we can use in our studies is huge. Some packages duplicate their own functionality. I recommend always paying attention to the execution time of each function. Looking for a faster solution, we should first search the web for similar functions in other packages. Often it’s also worth investing some time and developing (learning) your own solution, using simple functions that speed up the process from another package (satisfaction guaranteed).
Remember that R works fastest with matrices and vectors. The longer you use simple structures, the faster your solution will work.
Where to look for packages we can use?
If you are looking for packages related to geoprocessing in the broadest sense, I would first refer you to the list at the link, which contains most of the solutions in this area:
R packages are developed by the community and, most importantly, there is extensive documentation for each of them, sometimes with tutorials on how to use a particular package. If you are looking for a detailed description of the contents of a package, first look for it in the list of available packages at the link:
or use the Google search engine.
When you select a specific package, e.g. Raster, you will be redirected to a subpage with basic information about the package, files to download (manuals, tutorials, package source, packages related to the described package):
I usually use Google browser to browse such a large set of tools that R has available.