Take some time and sit through some videos on how to set up your 7sv. It's really worth your time.
Setting up the transducer angle is an amazingly important detail to get right. My HDS Gen3, has down and side scan, just like your Garmin unit. I wasn't impressed until I got the transducer level when the boat is loaded, in the water and underway at my usual searching/scouting speed. Once I got that sorted out, the side scan came alive. There's videos on how to find that under way level angle and get it to your transducer while on the trailer. It's actually simple to do, but not something you can hope to eyeball--and something Lowrance (in my case) doesn't talk enough about.
If you have someone rigging for you; then the boat needed to get on the water to figure out the setup angle for the transducer.
You do know that the finder isn't going to actually catch the fish, right?