Copyright & Security Questions

Hi,
I got couple basic but important questions, thank you for helping.
I installed Start Up template with quickstart package, as i know all demo pictures are changed with the GK DEMO pictures when we install. But in my website ( http://www.agirsaglam.com ) the background picture ( guy running ) is open, not GK DEMO. Is it okey me to use this picture?

Another question that bugging me is about adsense. Can i use google ads on my websites? Also, am I allowed to sell something on my website?

The last thing I want to know is about security. I am really beginner in Joomla and website stuff, what should I do to secure my website from potential threats? Any ideas about passwords, backups, security extensions, etc.?

Best regards, Furkan.

Hi

You can use Your site for any reason with a content attached to quickstart or in rest_files package.

For security I would advice to use RSFirewall (payed extention, but really good) and to manage backups Akeeba Beckup component is free and best available.