I am a pega beginner and I am required to create application.
When I see applications which was created by others, I recognized green box flow shape is configured as flow action. On the other hand, my Flow Shape is configured as Route to and I set flow action in connector. Is there any impact if the different style is mixed in the same application??
I think you are getting confused between process flow and screen flow.
Based on the 2 screenshots you have shared, one is a screen flow assignment configuration and the other is process flow assignment configuration.
In process flow, when we use an assignment shape in flow we specify the routing info in the "Route To" and we define the flow action rule on the connector coming out of that assignment.
However, in case of screen flow, the flow action is configured on the assignment shape and the routing info configuration part is not present on each assignment shape as screen flows cannot be routed to multiple users and it stays with one user only. Rather the routing info is configured on the start shape of the screen flow.