As MonoGame 3.8 went full .NETCore, you don’t even need a IDE to start making games on any desktop platform, including on a Mac. (High Sierra and up!!)
Firstly install .NETCore 3.1 for Mac: Download .NET Core 3.1 SDK (v3.1.404) - macOS x64 Installer
Once installed, go to terminal and type to install the templates:
dotnet new -i MonoGame.Templates.CSharp::3.8.0.1641
Choose a location to create your monogame game project and type:
dotnet new mgdesktopgl -o YourGameFolderName
Then go to your newly game folder location:
cd YourGameFolderName
Install monogame content builder:
dotnet tool install --global dotnet-mgcb --version 3.8.0.1641
Install monogame content builder editor:
dotnet tool install --global dotnet-mgcb-editor --version 3.8.0.1641
Register it:
mgcb-editor --register
Open the mgcb-editor to manage and build your game assets: sprites, sounds, music, etc.
mgcb-editor
Then you simply type to build your game:
dotnet build
Or/and type to run/test your game:
dotnet run
and then finally publish the game to any desktop platform you want:
dotnet publish -r osx-x64 -c Release
dotnet publish -r win-x64 -c Release
dotnet publish -r linux-x64 -c Release
EDIT: You also can build a single file for distribution adding /p:PublishSingleFile=true at the end of the line. Ex:
dotnet publish -r osx-x64 -c Release /p:PublishSingleFile=true
Then just go to YourGamerFolder/bin/release folder and the binary is now ready to distribute 
MonoGame also supports iOS and Android, but it relies on Xamarin, so development using Visual Studio for Mac will be mandatory. Hope it helps!