r – Error: “there is no package called …” and trying to use install.packages to solve it

The R studio I have in my university computer gives me an error when I try to download different packages, whereas when I’m with my laptop in the university server, I don’t get this error. Because of this, I don’t think that there is some kind of a proxy/server problem.

library(readr)
Error in library(readr) : there is no package called 'readr'

I also tried to download the package using R.exe program or download other packages and it gave me the same error.

After looking for a solution in the internet, I found this script:

install.packages('readr', dependencies = TRUE, repos="http://cran.rstudio.com/")

But it downloaded many different packages:

I would like to know the reason why RStudio gives me this error and what happened when I tried to download readr package using install.packages?