Sharing in Power BI is quite simple, but you'll want to consider what your goal is first. If your goal is simply to share a view-only version of a report or dashboard that users could engage with, the basic sharing mechanism can do that. If your goal is instead to allow users to also edit the report, you will want to use workspaces. Lastly, if you want to logically package reports and dashboards together, and have the ability to have fine-control over which reports can be seen by default, consider using Power BI apps.
The easiest way to share a dashboard or report is to simply click Share in the upper-right corner of any report or dashboard. Simply type the email address of the user that you want to share with and what type of access you want to give them. While you can't allow them to edit the report or dashboard, they will be able to view and reshare the report themselves. At any time, you can also see what assets are shared with you by clicking Shared with Me from...