Find your Form Name and ID by opening the page containing the form you want to track.
Right click on an element of the form (such as a field, button etc), then choose 'Inspect element'. You'll be presented with the page code. Look for the opening <form> tag by pressing Ctrl and F at the same time and typing <form, an example of the result is shown below:
The Form ID is "signup" but no Form Name has been specified so when configuring the form in app we need to add in the Form ID and leave the Form Name field blank.
We can absolutely track forms that only have either a Form Name or Form ID but if both are present we need both to be entered in the configuration. Also if your form has neither element you can leave both fields blank.
To check the details of an existing form in app go to either Edit to the right hand side of each form in your dashboard or, when a form has been selected, you can click Edit Form in the top right hand of any report - both routes will take you to the Edit Form tab (image above).