Data Loader is a widely used tool provided by Salesforce by which we can process a large number of records at ease, at a minimum of 200 records batch, rather than processing every single record manually.
Superbadge Apex Specialist looks good on Resume, and they prove worth as well. You should definitely complete the task on your own and you can get all the help.
Dashboards in salesforce help facilitate you with a quick snapshot of all stats in one analytical view. Dashboards and reports are analytical features.