Haven't found the cell phone type. So app recommendation can be misleading.
As you have no clue about that technical stuff, look for a good hiking map, which can already show the hiking trails or a special guide like
wise pilgrim. So you don't need to dive in the technical stuff.
I find OSMAnd (Android) acceptable (almost easy) for a start. Offline maps can be downloaded from within the app and the hiking view shows most trails, supermarkets, albergues and restaurant. It can also route me to the next albergue offline. So I can put the phone in flight mode and save battery / data costs.
"routing" is the answer to the situation "I'm lost! Ho do I get to the next ...".
A track is just a list of coordinates. Most apps show you this as e.g. red line on the map and put some icon for your current position. So you can check if you are on that track or not. The most easiest track is only the coordinates of village A and B. The result wil be a straight line between A and B. Good tracks have several hundred positions and follow all curves of the way.
The coordinates will be usually collected in the same apps that you use to view them. Some people walk the trail and share it on wikiloc.com and other sharing platforms, others just plan their next trip and "paint" these tracks with some tools and store it also. "Paintings" can be beautiful, but not all come close to reality.
