I just mounted this unit to the bow and have a  Tripple -Shot (with side scan) at the console. How do I find out,  before purchasing, if my lakes are included one the chip. 
any general tips would be appreciated. I’m not new to depth finders, but charts and way points are an area I need to learn. 

I assume that Navionics is the card in question.  You should be able to go to the web site for the type of sd card that you want.  You should be able to find the correct region and get a lake list to look at.

Both C-Map (Lowrance's mapping brand) and Navionics (Garmin's mapping brand) allow you to preview their maps on their websites. The only C-Map card compatible with your unit is the Discover map card which covers the majority of North America. To preview what the maps look like, go to https://www.c-map.com/chartexplorer/ and be sure to select the Discover/Reveal option and leave the toggle off for shaded sea floor as that's only available on the Reveal card. 

If you're looking at Navionics, only Navionics+ is compatible with your unit. https://www.navionics.com/media/wysiwyg/docs/Compatibility_Guides/GPS_Plotter_Cards_Compatibility_Guide.pdf This will show you what features will work on your unit and going here https://webapp.navionics.com/#boating@6&key=sfrrGjkmfP will allow you to look at their maps as well as the "sonar charts" aka user gathered and uploaded data to help build better mapping.