Fish finder newbie

Okay, so there are no "dumb" questions right? Well, I've never used a FF before and need a little jump start.
I've mounted mine on the transom so that the pointy end is toward the bow. It is below the bottom when it is in the down/locked position. Here are my questions...oh it is a Hummingbird 170 dual beam.
1. What area will I see on the screen? Behind the boat, right under the boat or ahead of it?
2. From what I can see, the dual beam appears to have one narrow and another wider. What is the difference?
3. The temperature sensor is on the transducer, so is the temperature displayed the surface temp?
4. Is the "fish identifier" worth turning on or does it just give false readings?

Most of the lakes I fish are less than 20 feet deep.
Thanks for the help.
Steve

The easiest way to understand the "CONE" you will be seeing is to take a flashlight and point it at the ground the area of light is your cone just like under the boat
In shallow water your area of view is smaller just like holding the light closer to the floor.
Think of the dual beam as the difference between a spot light and a flood light..
What you are seeing....
just about everything you see will be behind you.
on the screen you only need to watch the rite edge of the screen that is what you are going over as it passes across the screen you are getting farther away from the object

The fish ID will give you false readings most of the time. i don't use that feature.
the temp probe is giving you surface temps

I hope this helps

Someone can probably answer better than me but here it goes.
1. you should see straight under the transducer. In water 20 or less, you not going to be covering a huge area. Some instruction books will give you the angle of your signal so you can figure out how wide of an area you are covering by the depth.
2. Mine has an 85 frequency and a 200 if i'm not mistaken. The 85 is narrow giving you a detailed picture. the 200 covers a lot more area without as much detail. Mine has a dual screen that splits the screen so you see both. I us this a lot. It has won a tournament for me when we went half a day without a bite. I just ran around watching the screen and discovered the fish were staging in deeper water than we were fishing.
3. Read your manual. Usually the fish ID mode will help a beginner understand his FF. Dedicate a couple of hours just using your FF. When the fish ID shows fish, turn the id mode off and look at the same area.

Good luck

Thanks guys, that'll help me get started and understand what I'm seeing.