When LR brings in your RAW images, it MUST do a conversion to display them on the screen. The initial image you see is the JPEG preview your camera created by default as part of the RAW creation process. In order to show you the image on your screen, LR must create a preview, or RAW conversion to show the image on screen.

You can change how LR does its default imports fairly easily.

Change the Preview you use:

If you do not like the LR created preview, you can use the camera created one:

If you go to your Import screen, you can change how it renders previews. So "Import" then on right hand side, look at "File Handling". Choose an option under "Render Previews". Here you tell it to use the ones from the camera, by selecting 'Minimal' or 'Embedded and Sidecar". However, if you need (ie zoom in) a higher resolution preview, LR will later render it using LR conversion. (and slow things down). This will choose the preview to use for each import.

Change the Default Rendering

I believe this is the one you were looking for: If you really want to change ALL previews, for ALL images from your camera and have them look like your camera previews, then simply take any image, perhaps one you shot in RAW+JPEG so you can compare to your camera settings. Then do a basic edit using the Develop Module. Adjust White Balance, Tone, Presence, Curves, Sharpening, etc. Keep this basic,not specific to the image. When you are happy, then choose Develop>Set Default Settings and select "Update to Current Settings". Now LR will import using these settings by default for all images from this camera. So, why shouldn't you do this: you may find this doesn't work for all your images, and then you must edit each image to remove it. There is no Undo available, but of course you can remove the results of the edits.

Use Import Develop Settings

The alternative, is to use Auto Import Develop Settings to apply your preferred default settings to every photo you import. So:

1. Go to Develop Module. Edit an image using your personal, basic settings as mentioned above.
2. On left hand side, find 'Presets' area. Click the '+'. Select the items you wish to save, then name the preset. Save.
3. Choose, File> Import. On right hand screen you will see "Apply During Import" and a drop down for 'Develop Settings'. Choose your named preset. Import.

Now, you have the ability to create many presets, for different conditions or venues, and apply them at import. This works in a similar way to the 'Set Default' above, but you can have many different ones or choose none.

For what its worth, here are my own default import settings:

WhiteBalance As Shot
Auto Tone
Clarity +45
Vibrance +15
Saturation +5
Sharpening +65