The easiest way is probably to install Jaguar https://github.com/toitlang/jaguar
I would very much recommend the Visual Studio Code extension when you are starting out with the language. Will give you a lot of help and hints around the syntax. But you can use any editor.
Run a program on the desktop with `jag run -d host myprogram.toit`
Install the `host` package for non-embedded things like files, pipes and subprocesses:
# Make this directory into a Toit project.
touch package.yaml
# Install the host package
jag pkg install host
Other packages like http or mqtt can be found at https://pkg.toit.io/