Absolutely, it is possible to pre-populate any desired information into the form before clicking on the 'Save' button.
In the Web Portal, go to Forms > Start New Form > Prefill the information that you would like included in the webform that you're sending > select Convert to Webform > Save > Email Link.
If you're using CRM elements, then you will need to fill out those fields before sending the Webform, as the customer will not have access to your database.
Please refer to the video guide below for a step-by-step tutorial.