You are not showing any error message, just normal installation messages. As far as we can see you have successfully installed ggplot2 in your system.
This is just an informative message that is letting you know that since you haven't specified otherwise, the package has been installed on the default package library.
It looks like you installed the package in your library but did not load it into the environment with the library() function. You install packages once and then load the ones you want to use for each r session. Try running library(ggplot2).