Got my Hook 7 ordered and will be putting it on a 2017 Trident 15.
Never installed one. Anyone have tips for this yak?
What all do I need to buy?
I got a battery and nav plus ordered.

What you're going to need depends on how you are going to mount the unit, transducer, and battery. I would look for videos on YouTube to see how other Trident owners mounted theirs to get ideas and make a shopping list. I bet you'll like your Hook7-here's a screenshot from my Hook 4.

Man that looks awesome.
I'm going to have to learn to use mine. How do you know when you're seeing what's directly below you since the screen scrolls?

Your Hook has a feature where you can scroll back using the arrows on your unit. You can even scroll back and drop a waypoint in a place you passed over in the past. Every time you go out, you'll get better at using it.

The right edge of the screen shows what is coming into the cone put out from the transducer. Think of where your transducer is mounted. Figure out which frequency you are using to help you figure out how large the cone is based on the depth of the water you're in. As the objects are passing under you they are moving to the left on your screen.

Go out and play with your screen when you don't need to be fishing. Find known objects under water and approach them to see how they look on your screen. Take a few medium rocks out and drop them so you can see what moving items look like on the screen.

Phil