I'm 69 and I don't need simple step-by-step explanations. 🤷♂️ [semi-teasing]
As gbarringer well cites the 'aftermarket' Garmin SD card is straightforward as the vehicle already has the hardware & firmware that will recognize same. He's the resident expert on same so if you go this route you'll have plenty of setup guidance available.
I'm fairly new to Waze but also find it of value and of course it's always up to date to include user feedback insights. My daughter has been relying on Waze almost since inception and finally got this ol' dog to learn a new trick. We both use the Weathertech cupholder mount and it's a simple solution.
Most of the time I know at least generally where I'm going (ol' school pre-flight) so all I really want is to hear some confirmation that I'm proceeding as planned. I do appreciate a visual display but typically it's just for an orientation glance, keeping eyes on the road, and again audio is what I value most.
Since you have an iPhone give the Waze App a try. If you want more then the Garmin SD card is the way to go.