To get started, there is no such thing as iOS X. iOS is an operating system for mobile devices such as the iPhone or iPad. Mac OS X is the operating system for computers, such as your MacBook.
If, as your settings suggest, you already have Mac OS X 10.6.8 on the MacBook, updating to a newer version of the Mac OS is fairly simple. First you need to determine what your MacBook will support.
The most recent version of Mac OS X is 10.8 (Mountain Lion.) System requirements for it can be found on this page. In particular you will see that for a MacBook the model must be Late 2008 Aluminum or Early 2009 or newer. You also need at least 2GB of RAM. More is recommended.
If you cannot run Mountain Lion, you may be able to run Lion (Mac OS X 10.7.) System requirements for this can be found on this page. Most important is that you need an Intel Core 2 Duo processor and at least 2GB of RAM.
Please note that both Lion and Mountain Lion remove the ability to run older software that was designed for Power PC Macs (ones that ran with pre-Intel processors.) An example of this is Microsoft Office 2004 or earlier. If you have any like this, be prepared to update that software, as it will never run under the later operating systems. Check with the makers of the software that you use to find out if their software is supported.
To get either of these operating systems you will need to sign in the Mac app store, which most people will find in their Dock. The icon looks like a blue disk with a white A in it. If you are only going as far as Lion, you will need to contact Apple's sales team in order to purchase a download code. In the USA the phone number for that is (800) MY-APPLE. If you reside elsewhere you can find the phone number on your country's Apple store web page, in the upper right corner.
Anyway, in the App store, for Lion enter the code you purchase, or for Mountain Lion search for it, purchase it and download. Installation takes place automatically.
You can also change your password for the computer. Go to System Preferences (under the Apple menu) select Users & Groups, select your user and click the Change Password... button. Follow the directions.
Hope this helps you. Best of luck.