Hey Earl, welcome aboard!

Your camera has a different set of features than my older model and presents some interesting options. You should practice with your camera before leaving and confirm which features, functions work best in your hands. Reading your manual, but not having that specific model in hand, it seems the three options of your question all relate to using the Live View and focusing via the LCD display on the back of the camera. I've found Live View works best when I have the camera mounted to a tripod and I can zoom 10x into the details.

If you use your viewfinder (holding the camera to your eye), this would be the 'more traditional' method for a DSLR. You'll probably use One-Shot AF as described on page 97 for your entire Alaska trip. You might practice the buttons, dials needed to move the active AF point around the viewfinder with the camera held to your eye. Or, practice looking the scene, deciding where you plan to focus, select an off-center AF point, and then look through the view-finder and arrange / adjust your shooting position to match the subject to the preset AF point.

Have a great time and feel free to ask questions, probably better in the Main Section, where a wider audience will see the question. Consider the several 'scene settings' as these provide a lot preset 'logic' available from the camera to match your situation, especially Landscape for your outdoor work.