You can import a MS Project file or some sample templates from the File menu. In case you are not already signed in, you can click on the Sign In option at the top right corner of the main interface.
By signing in, all your work is saved online.
To share your MS Project file you can choose Share from the File menu.
You will be given a URL that can be used for sharing your MS Project file. You can also click on Email a Link option to instantly open your default mail client for emailing the file.
Other than many self explanatory options, AmiProject provides a large array of sample templates that works as demo projects for assisting you in exploring ideas for project creation. These templates include, annual report preparation, commercial construction, customer feedback monitoring, internal readiness training, etc.
Thanks to Denis Bondar for this tip!