I want to turn the camera to get the view I want, but everytime I turn the camera, I need to go to render window to check if it's the view I want. I turn the view with my mouse cursor, but that does not affect the actual camera view in rendering, can I set the camera view the same as I turn my cursor?
You can enable camera lock, so your camera moves as you're looking through it.
Check it in Sidebar > View > Lock Camera to View
Then press Numpad 0 to view through your camera.
Now just move, zoom and your camera will exactly follow.
You can switch it on and off as you like.
Set your viewport the way you want it and then press Ctrl + Alt + NumPad0, this will do following: set camera to fit your view, set your view to the camera.
Another way, would be to select camera, press NumPad0, this will set your current view to camera, and any changes to camera's position/rotation will be instantly visible on the screen.