Install Composer (Globally) first:
Best to install from the home directory
$ cd /home/bitnami
$ sudo curl -sS https://getcomposer.org/installer | php
$ sudo mv composer.phar /usr/local/bin/composer
Make sure Composer's global bin directory is on the system PATH (recommended):
$ sed -i '1i export PATH="$HOME/.composer/vendor/bin:$PATH"' $HOME/.bashrc
$ source $HOME/.bashrc
* Info here: https://getcomposer.org/doc/00-intro.md#system-requirements
Install Drush
Best to install from the home directory:
$ composer global require drush/drush:dev-master
After following the instruction on setting up VirtualBox and the Bitnami LAMP stack and then installing the Guest Additions and getting SSH hooked up, you’ll use SFTP to connect to the bitnami VM and copy over the Drupal files. You’ll need to chmod some directory within your home directory within your bitnami VM to alloy the SFTP client to transfer files.
Tip: The best method for moving your files from Drupal to your test site is by using Git to download the files right into your Bitnami home folder and then moving the whole directory and files into the root directory fo your server. If you must FTP from the host machine into your Bitnami VM, tt is immensely faster to copy the compressed file over to the Bitnami VM and then uncompress once it has arrived rathe than decompressing and FTPing the files.
Once you have copied the files over, uncompress them and move them to /opt/bitnami/apache2/htdocs/drupal
Next you need to do some permissions things to allow apache to install the Drupal site.
$ sudo chown bitnami:daemon -R /opt/bitnami/apache2/htdocs/drupal
Then you need to use MySQL to create the database
Then you can install Drupal and start working with it.