There are several R packages, such as dplyr, tidyr, stringr, broom that provide excellent tools for data wrangling. Most of them are built by Hadley Wickham and collaborators. Base R also has some good functions that are useful from time to time.
The documentation available for free in this area is outstanding. Here are a few free resources:
- R Studio data-wrangling cheat sheet: https://www.rstudio.com/resources/cheatsheets/
- Hadley Wickham's "Data Science for R": http://r4ds.had.co.nz/