Dear Jane,
you can create a new post by clicking on the “New Topic” button in the top right corner of the form-homepage: Itasca Software Forum - Let’s help each other (itascainternational.com)
If you can not see that button you probably have not provided a license during your registration. As explained in the “Welcome to Discourse”-Post ( Welcome to Discourse - Itasca Software Forum (itascainternational.com)) you need a valid software license do post any questions. You can add a license to your account in the “Profile” tab of your accounts preferences.