What have you tried? How did it fail?

Basically, if you want a cron job, use a cron job.

The common problem with cron jobs is to assume that the cron job has the same environment and current working directory as an interactive session. This is not the case.

You will need to set up your cron job to run with a defined working directory and a defined environment. The easiest approach to doing that is to call your main program through a shell script like:

#!/bin/bash
set -ae

# load the environment
source ~/.bash_profile
source ~/.profile

# Set the working directory to the directory the shell script
# and Perl script live in:
cd $(dirname $0)

# Find the name of the Perl script:
THIS_SCRIPT=$(basename $0)
PERL_SCRIPT=${THIS_SCRIPT/.sh/pl}

echo "Running $PERL_SCRIPT"

# Launch it:
exec $PERL_SCRIPT
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Automate it to do what? Run? Delete all files from disk? Remind you for the thousandth time to formulate proper questions by adding all required information?

Note, you don't have to use a CPAN module to daemonize anything. Just run it as a loop in the background. Or if you wish to do it the "right way",

1. start "parent script"
2. set effective user id (setuid)
3. fork child process
4. kill parent

"...automate my perl script without cron..."

Set up your alarm clock. See also.

systemctl