To migrate a SharePoint 2010 environment to SharePoint 2013, what are the perquisites? What all the data points need to be collected before drafting a migration plan?
I recommend checking out the Microsoft article for a good overview: https://technet.microsoft.com/en-us/library/cc262483.aspx
But to summarize, after setting up your SharePoint 2013 farm, move over your databases and other relevant files. A useful PowerShell command for mounting your content database is Mount-SPContentDatabase (https://technet.microsoft.com/en-us/library/ff607581.aspx)
Edit: Additional information I found useful - here is an article for how to export your databases. Afterwards, just copy them over to the new farm. https://docs.microsoft.com/en-us/sql/integration-services/import-export-data/start-the-sql-server-import-and-export-wizard
SQL has a database export wizard that makes it easy.
Edit 2: As for data points to collect, see which databases / content databases need to be moved over. The size matters in the transfer process, especially if you remove into these servers and there's a limit to how much can be copied over at one time. Take note of configurations of items such as your service applications, site collections, etc. to verify after the migration. Certain service applications can be migrated easily / mounted like the managed metadata service.
Based on query, you wanted to know the step by step procedure to migrate a SharePoint 2010 application to 2013. Please checkout the informative articles to achieve your goal :
Overview of the upgrade process to SharePoint 2013
Upgrading a custom application to SharePoint 2013
Migrating SharePoint 2010 Solutions to SharePoint 2013 Apps
Upgrade databases from SharePoint 2010 to SharePoint 2013
Upgrade site collections to SharePoint 2013
alternatively, you may try the automated solution from here..http://www.topsharepoint.com/content-migration-tools-for-sharepoint