Can I download Google Chrome on my Mac and switch between it and Safari? I have a website update I need to do and don't want to change my mac but must use Google Chrome for the updates.
You can install Google Chrome and use it side by side with other browsers such as Safari (built-in), Firefox (need to download & install), and Opera (need to download & install).
One of the browsers will need to be set as your default. This can be changed in System Preferences > General.
It's worth noting, Safari is the default browser in all versions of OS X and iOS. Google Chrome is also a browser, and Yosemite is an operating system. Your question is a bit misguided. You don't necessarily "switch between Google Chrome and Yosemite". That said, if you're talking about editing a website via online tools through web hosting providers such as Squarespace, presuming they support Chrome they'll also likely support Safari. I'd suggest first trying to update the site in Safari before you download and install a browser which you may not even need.