I have the suspicion that this is not related to RStudio Cloud but to basic R usage, you are showing commands that include a variable assignment and you are saying that you are not seen a numerical result, but are you aware that when you use the assignment operator <- the result of the command on the right-hand side, gets stored on the variable of the left-hand side? so if you want to check the value that gets stored on each variable you have to type the name of the variable on the console, for example:
avg <- mean(iris$Sepal.Length,na.rm=TRUE)
avg
#> [1] 5.843333
Created on 2020-03-03 by the reprex package (v0.3.0.9001)