You will need root privileges for any the following. To get root, open a terminal and run the command
sudo -i
and the command prompt will change to ‘#’ indicating that the terminal session has root privileges.

Alternative #1: Add commands to /etc/rc.local

vi /etc/rc.local
with content like the following:
# This script is executed at the end of each multiuser runlevel /path/to/my/script.sh || exit 1 # Added by me exit 0

Alternative #2: Add an Upstart job (for systems older than 15.04)

Create /etc/init/myjob.conf
vi /etc/init/myjob.conf
with content like the following
description “my job” start on startup task exec /path/to/my/script.sh

Alternative #3: Add an init script (obsolete)

Create a new script in /etc/init.d/myscript.
vi /etc/init.d/myscript
(Obviously it doesn’t have to be called “myscript”.) In this script, do whatever you want to do. Perhaps just run the script you mentioned.
#!/bin/sh /path/to/my/script.sh
Make it executable.
chmod ugo+x /etc/init.d/myscript
Configure the init system to run this script at startup.
update-rc.d myscript defaults

Content retrieved from: https://askubuntu.com/questions/228304/how-do-i-run-a-script-at-start-up.