To use yourself the code you can scan the code by app inventor server. To share it you need to download the apk file to your computer, upload it to your dropbox or google site. With your own URL you can generate a QR code in a website like www.is.gd and finally to share the QR you can uploaded to your blog. Remember to give permissions to execute downloaded apps from internet in your Android mobile.
Please always use the new version. If you have insourmountable difficulties with the use of the new appinventor, you could use MIT App Inventor old version
You just need App Inventor, your Google account, and a USB connector for your Android mobile to start creating your own apps.
Remember that you must send your codes in APK format to our Moodle course before deadline (one week) and add a youtube video in your personal wordpress blog to show it working.