Explanation
Guided selling, validation rules, and required fields on the page layout are three options that can be used to ensure sales reps fill out key fields when working on an opportunity through the process. Guided selling allows administrators to add prompts and guidance at each stage of the path to help reps move forward with confidence. Validation rules allow administrators to enforce data quality and business logic by preventing reps from saving records that do not meet certain criteria. Required fields on the page layout allow administrators to make certain fields mandatory for reps to enter before saving records. Configuring opportunity path can help reps visualize and update key fields at each stage, but it does not make them required or prevent them from moving forward without entering them. Using flow to mark fields required is not possible because flows cannot modify page layouts or field properties. References:
https://help.salesforce.com/s/articleView?id=sf.path_guided_selling.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.validation_rules.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fields_defining_field_properties.htm&type=5

Explanation
Formula fields are types of fields that calculate a value based on an expression or formula that references other fields or constants. Formula fields prevent administrators from changing their field type once they are created because they may be referenced by other functionalities such as reports, validation rules, workflow rules, etc., that depend on their data type and value. If a formula field is referenced by other functionalities, then changing its field type may cause errors or unexpected results. References:
https://help.salesforce.com/s/articleView?id=sf.fields_about_formulas.htm&type=5

Explanation
Flow Builder is a tool that can be used to create an automated way to delete records based on field values.
Flow Builder can create flows that define the logic and actions for deleting records, such as finding records that match certain criteria and deleting them in bulk. Flows can be scheduled to run at regular intervals or triggered by other events or processes. References:
https://help.salesforce.com/s/articleView?id=sf.flow_builder.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.flow_concepts_delete.htm&type=5

Explanation
Setup audit trail is a tool that allows administrators to review recent configuration changes made in their org. It shows a list of up to 180 days of setup changes made by anyone in the org, including the date, time, user, and type of change. It can help administrators track who made what changes and when, and troubleshoot any issues caused by configuration changes. Critical updates are notifications that inform administrators of new features or enhancements that may impact their org; they do not show configuration changes made by users.
Debug logs are records of database operations, system processes, and errors that occur when executing a transaction or running unit tests; they do not show configuration changes made by users either. Field history tracking is a feature that allows administrators to track changes to the values of certain fields on records; it does not show configuration changes made in setup. References:
https://help.salesforce.com/s/articleView?id=sf.monitorsetup.htm&type=5

Explanation
A Trailhead Playground is a free, online learning environment that allows you to try out Salesforce features and apps. You can use a Trailhead Playground to test out an app from the AppExchange before you install it in your production org.
A sandbox is a copy of your production org that you can use to test changes and new features. You can install an app from the AppExchange in a sandbox to see how it works in your environment.
Testing an app in a production org is not recommended, as it could affect your live data. Checking edition compatibility is important, but it is not a way to try out an app.