The A1278 designation refers to MBPro models from mid-2009 to 2012. If your laptop is actually 2010-2012 model, then it may have access to Internet Recovery Mode using Command + Option + R (this is only possible if the laptop at one time had macOS 10.12.6+ installed so the firmware has this capability). This will be the easiest option to reinstall macOS if you don't have access to another Mac with a model designation from 2007 to mid-2020.
If the laptop is the 2009 model, then you can use any retail version of the OS X 10.6 Snow Leopard upgrade DVD (one with a picture of the cat on it) to get started with macOS. We can provide more details on how to upgrade to later versions of macOS.
If the laptop is a 2010 model, then you must use the gray OSX recovery DVD which originally shipped with that laptop from the factory since the retail upgrade DVDs are unlikely to be compatible as a 2010 laptop had a customized version of Snow Leopard. If you have the gray recovery DVD for this specific model 2010 laptop, then we can provide more details on how to upgrade to later versions of macOS.
If you have access to such a working Mac, then let us know and we can provide more specific details on which version(s) of macOS you can download & create a bootable macOS USB installer if Internet Recovery Mode doesn't work and if the installation DVD options are not available or applicable.
FYI, ignore most of what you will find online as it will not work for reinstalling macOS using various hacks or Windows utilities.