If a form is added to a landing page, the submissions will be reported on the form. A form is a web element that allows you to collect information from your prospects, such as their name, email, or company. A landing page is a web page that you create and host in Marketing Cloud Account Engagement to showcase your products or services, offer content, or register for events. You can add a form to a landing page to capture leads or convert visitors into prospects. When a prospect submits a form on a landing page, the submission data will be recorded on the form report, which shows you the number of views, submissions, errors, and conversion rate of your form

According to the [Salesforce documentation], when a new lead record is created in Salesforce without an email address, and the Salesforce connector is set to automatically create prospects in Marketing Cloud Account Engagement, no new record will be created in Marketing Cloud Account Engagement. This is because email address is a required field for creating a prospect in Marketing Cloud Account Engagement, and without it, the lead record cannot be synced or matched with a prospect record. A visitor record is created only when a person visits a tracked web page, not when a lead record is created in Salesforce. A new account will not be created either, as accounts are synced from Salesforce to Marketing Cloud Account Engagement based on the account ID of the associated lead or contact record. A new prospect record will not be created, as explained above. Reference: [Salesforce documentation]

An identified visitor is a visitor who has provided their contact information in a Marketing Cloud Account Engagement form. This means that the visitor has converted into a prospect and has a record in Marketing Cloud Account Engagement. Marketing Cloud Account Engagement can track the activities and behavior of identified visitors using a cookie that is placed on their browser when they fill out a form. Identified visitors are different from anonymous visitors, who have not provided any contact information and are only tracked by their IP address, and from visitors whose organization has been identified using a reverse IP lookup, who may or may not have a prospect record in Marketing Cloud Account Engagement

The automation tool that the Administrator should use to create this list is a dynamic list. A dynamic list is a list that automatically populates with prospects who match the criteria you set. You can use a dynamic list to segment your prospects based on their attributes or behaviors, such as their opportunity stage, score, or email activity. A dynamic list is constantly updated, so prospects are added or removed from the list as they meet or no longer meet the criteria. A dynamic list is ideal for creating a list of prospects who are in the prospecting stage of the opportunity, and removing them from the list once they move to another stage.

By default, Marketing Cloud Account Engagement writes to two objects in Salesforce: contact records and lead records. These are the two objects that store information about individual prospects in Salesforce. Marketing Cloud Account Engagement syncs with these objects based on the email address field, which is the unique identifier for prospects. Marketing Cloud Account Engagement can create new contact or lead records in Salesforce, or update existing ones, depending on the sync settings and rules. Marketing Cloud Account Engagement does not write to case records, opportunity records, or account records by default, but it can read from them and use their information for segmentation and reporting purposes. Reference Marketing Cloud Account Engagement and Salesforce Sync Behavior