You can do this as follows:
1. Use the "create" action button in your datagrid.
2. Using a microflow, with the activity "Create object".
3. It is even possible to select an entity for "Generate Overview pages" with right mouse click. The standard CRUD actions are then realized immediately.
Furthermore, I would advise you to follow the learning path "Rapid developer". All standard Mendix functionalities are covered there with good examples: https://gettingstarted.mendixcloud.com/link/path/38
I hope this helps!
A screenshot of what I mean with option 2: