The migration process migrates all Sitefinity content - such as users, news items, pages, page templates, etc. However, you might need to re-create all custom widgets and modules ( which are not present in 5.x ) as the migration module does not support migrating of custom code.
After you migrate your 3.7 content to 5.4 and configure it accordingly, you can register a domain in our system for your license and deploy your site to that domain.
The following article can be useful to you:
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items