read_csv error message

I can't seem to get my csv file to read. Here is my code and the error message that keeps showing up. Please help I'm struggling to learn.

install.packages('tidyverse')
install.packages('readr')
library(tidyverse)
library(readr)
read_csv(dailyActivity_merged)
read_csv("dailyActivity_merged.csv")

read_csv("dailyActivity_merged")
Error: 'dailyActivity_merged' does not exist in current working directory ('/cloud/project').

read_csv("dailyActivity_merged.csv")
Error: 'dailyActivity_merged.csv' does not exist in current working directory ('/cloud/project').

You want the file name in quotes.

Check to see that the file does exist in that directory.

Missing the ".csv" extension.

Hope this helps a little.