Report type is a tool that can be used to pull contact fields into the custom report for Event. Report type defines the set of records and fields available to a report based on the relationships between a primary object and its related objects. To edit the custom Event report type and add fields related via lookup, go to Setup > Report Types and select the Event report type. Then click Edit Layout and drag the fields from the Contact object to the layout. Reference: https://help.salesforce.com/s/articleView?id=sf.reports_builder_create_report_type.htm&type=5

Report folders are used to organize and secure reports in Salesforce. You can set different levels of access for different users or groups on each report folder. To preserve the integrity of the source reports for dashboards, you can create a new report folder with viewer access only and move the dashboard reports to that folder. This way, users can view the reports but not edit them. Reference: https://help.salesforce.com/s/articleView?id=sf.reports_folders.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.reports_dashboard_folder_access.htm&type=5

Currency locale and default language are two of the company settings that an administrator can configure in Salesforce. Currency locale determines how currency amounts are formatted and displayed in reports and other places. Default language determines the language used for labels, buttons, tabs, and other elements in Salesforce. Reference: https://help.salesforce.com/s/articleView?id=sf.admin_supported_currencies.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.admin_supported_languages.htm&type=5

Account and contact are two records that can be created when using the lead conversion process. The lead conversion process converts a lead into an account, a contact, and optionally, an opportunity. Reference: https://help.salesforce.com/s/articleView?id=sf.convert_lead.htm&type=5

Two data loss considerations when changing a custom field type from Text to Picklist are:
Assignment and escalation rules may be affected, because the values in the picklist may not match the values that were previously entered in the text field, and the rules may not trigger as expected.
Any list view based on the custom field is deleted, because the filter criteria for the list view may not be valid for the new field type, and the list view cannot be displayed. There will be no data loss with use of a global value set or auto updates to Visualforce references, because these are not related to changing a custom field type from Text to Picklist. Reference: https://help.salesforce.com/s/articleView?id=sf.fields_changing_type_considerations.htm&type=5