If you are wondering how to download the datasets in rstudio this code will get them for you
library(readr)
urlfile <- "https://raw.githubusercontent.com/fivethirtyeight/data/master/fandango/fandango_score_comparison.csv"
previous <- read_csv(urlfile)
urlfile2 <- "https://raw.githubusercontent.com/mircealex/Movie_ratings_2016_17/master/movie_ratings_16_17.csv"
after <- read_csv(urlfile2)
This was found using the following google search: download csv from github in rstudio using this method