A 2011 Mac has access to Internet Recovery Mode using Command + Option + R which theoretically should boot to the macOS 10.13 High Sierra online installer for this laptop.
FYI, before you wipe out any OS, you should plan ahead on how to reinstall the old OS. Even though Internet Recovery Mode is an option for a 2011 Mac, it does not always work due to local network issues (home network, or local Internet & ISP issues), plus Apple has been dropping the ball recently on having their Apple servers being able to download some older versions of macOS for older systems like a 2011 Mac.....so as an added precaution it would be advisable to create a bootable macOS USB installer while macOS is still working.
Here is an Apple article with instructions for creating a bootable macOS USB installer (the most reliable method available):
Create a bootable installer for macOS - Apple Support
You can use another working Mac compatible with macOS 10.11 El Capitan or macOS 10.13 High Sierra to create a bootable macOS USB installer.....that other Mac can currently be running any version of macOS 10.6+. Generally you need a Mac from 2007 to mid-2018, but there may be some exceptions so you can use the information in the following article to confirm OS compatibility with various Apple hardware:
https://eshop.macsales.com/guides/Mac_OS_X_Compatibility
macOS 10.13 -- a Mac model Late-2009 to mid-2018
macOS 10.11 -- a Mac model 2007 to 2015
FYI, if you only have access to a Mac from 2007 to mid-2009, then you will need to start by installing macOS 10.11 El Capitan, then once installed, upgrade to macOS 10.13 High Sierra.
