How to run a command after a delay at login with .bashrc

I'm trying to run a command line on .bashrc after 20 seconds so I'm doing

sleep 20 && cp text1.txt text2.txt

But the system will not start until the 20 seconds go by, and then it will start. Is there anyway the system can start and then execute after 20 seconds the command script?

Run the command in the background using "&"

sleep 20 && cp text1.txt text2.txt &

The shell job ID (surrounded with brackets) and process ID will be printed on the terminal:

[1] 25177

To suppress the stdout and stderr messages use the following syntax:

sleep 20 && cp text1.txt text2.txt > /dev/null 2>&1 &

> /dev/null 2>&1 means redirect stdout to /dev/null and stderr to stdout