Hey Realm Games,
Here is a wiki page that talks about how to get the initial build of the engine working on Linux: A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums
You may want to check check the section header “Recent Mono versions” depending on which version of the engine you’re trying to build. That section mentions the same error you’re getting with the “unknown ToolsVersion ‘11.0’.” Hopefully this helps get you started with UE4 on Linux.
Cheers,