Unfortunately it's not quite that simple. If you attempted the OS upgrade and it wasn't successful, you will most likely continue to have errors until you wipe and reload your OS. However, if your device reboots and the errors go away, then you're most likely OK.
Upgrading your OS is not difficult, but it is not trivial either. It will be much easier to do, and you will be much more likely to be successful, if you first get some basic familiarity with your BlackBerry. A good way to do that is to perform the CrackBerry Memory Optimization Procedure that's linked in my sig. Created by Forums Moderator Reed McLay, it will show you how to install your device OS on your PC, (which you have to do to upgrade your OS) and will help you optimize your free memory. It's a terrific tutorial procedure. Once you've done that, and understand what's going on, upgrading your OS will be much easier.
You should not attempt to upgrade the OS in the first 30 days that you own a new phone, simply because installing an OS other than the factory-supported OS will void your warranty and you will have to restore the factory OS before you can return your phone, should you find some other defect in it in the first 30 days. As an additional benefit, after using it for 30 days, you'll be much more likely to succeed when you do attempt the upgrade.
In addition to all the above, if you are considering installing a leaked OS, consider CrackBerry's disclaimer:
*OS Disclaimer - Please Read: Keep in mind this is NOT an official release and as such is not supported by RIM or your Carrier. If you choose to install, do so at your own risk and only if you're comfortable in the process of upgrading and downgrading your device software. It is quite normal during operating system development for certain features to be crippled or disabled while others are tested, and these beta builds often reflect that. They are not always better. Depending on your BlackBerry comfort level, it may be best for you to wait for community feedback on a build before deciding to download and install for yourself or simply wait for the next official release. If you require support, you will find it in our CrackBerry forums via our extremely knowledgeable community base - do not contact your carrier or RIM for Beta OS technical support (their first course of action will be to advise you to downgrade to a supported OS).