Noob Linux user here, got Ubuntu 20.04.3 on a laptop and trying to get to a similar state to my main windows pc. I currently have a C# Windows Form application made in visual studio 2019 that I'm trying to get working on Linux using MonoDevelop but keep getting errors with the current main one being:

/usr/lib/mono/msbuild/15.0/bin/Microsoft.Common.CurrentVersion.targets(5,5): Warning MSB3088: Could not read state file "obj/Debug/courseworkTestOne.csproj.GenerateResource.cache". The input stream is not a valid binary format. The starting contents (in bytes) are: 06-01-01-00-00-00-01-0D-62-61-73-65-43-6F-6E-76-2E ... (MSB3088) (courseworkTestOne)

Never used MonoDevelop before and not too experienced with the inner workings of Visual Studio so I have no idea where to go from here and any help would be appreciated.

If you keep in mind that Windows Forms is Windows only, then you avoid all hours wasting on that dead end.

Mono WinForms and MonoDevelop are literally dead projects, so unless you are capable of reviving them yourself you should back off.