Check the boxes next to the topo maps on the list that you want to use. The DriveSmart 61 has three built-in maps, the name of yours might be slightly different depending on version
CN North America NT 2019.11 Parkopedia
CN North Ameria NT 2019.11 Foursquare
CN North Ameria NT 2019.11 ALL
The first one is used for finding parking spaces, the second one is POI's from Foursquare. You can leave these checked. The third one is the normal map that you see on the screen and you will have to un-check the box next to it, or you will not see the topo maps (typically - but there could be some exceptions to this depending on the map).
After un-checking the City Navigator ALL box, you should now see the map (assuming you are actually located in the area that it covers). However, I don't know what kind of "trip planning" you want to do. When the City Navigator map is un-checked, you will not be able to calculate any routes. In order to calculate a route, you need a map that contains routing information and I don't think the AZ topo can do this. In other words, it won't be able to give you turn-by-turn directions.
However you will be able to look at the map and mark locations to use with City Navigator. Tap the screen and a little flag should appear where you tapped. Tap the box at the bottom of the screen and tap the Save button if you want to create a favorite (also known as "saved locations" or "waypoints).