How you load it depends on the vehicle. Usually front end first. In any event, you have to run it far enough forward to load the tongue. I usually watch the rear of the tow vehicle as I move the load forward. Look for the tow vehicle to start to squat slightly.
Not a lot, just enough to make the trailer slightly nose heavy. If you don't get enough weight on the tongue, it will tow rather squirrely. (Like all over the road).
“To disarm the people is the best and most effectual way to enslave them”
- George Mason, American Statesman (1725-92)