If you have RStudio, you can go on the bottom right panel and click on Packages > install as specified here
Or directly with R:
# Install the package
install.packages("packageName")
# Load the library for the current script
library(packageName)
Once you start playing around with data, you generate graphs or you want to play with your results. I came across shiny dashboard which is a R librairy made by rstudio that provides exactly what you need in order to create dashboard.
It is rather simple and intuitive and has a good visual.