Need help with basic R exercise

First, I can't get R to read data file from my desktop.

Second, I'm trying to use 'tolower' function to convert all letters within the column 'company' to lowercase letters, but the tolower function doesn't seem to work either.

Lastly, if I were to run a function in the script, the imported dataset is supposed to change but it doesn't.

Here are a couple of examples that I'm trying to follow, but I can't get it to work on my R Studio

Can you post the codes that you tried so far?

As RuReady mentions, it'll be helpful to see your code and the errors you get.

Here's steps to create a reproducible example: