Hello everyone, I am an incoming research intern to HITS gGmbH this summer. I recently purchased a subscription for the Deutschlandticket and I have a couple questions as a newcomer to Germany's public transport system. I also have the DB Navigator App installed.

1. My apartment, without giving away the exact address, is close to Leistelle and the DEZERNAT 16 event venue. If I want to transit to HITS gGmbH, what would I input into the DB Navigator App as the stations ("From" and "To") on the booking tab? Will the app automatically search the station closest to my live location?
2. Can the DB Navigator App also be used to find routes with the ICE train and purchase tickets for ICE? My family will be with me from May 15 - May 22, so I am considering using the ICE with them for this period. I do not see the point to buy them the Deutschlandticket like for me.
3. When I arrive in Germany (FRA) and am ready to take the trains, do the tickets need to be purchased in advance online or can people also buy them in person?
4. Are the tickets QR codes to be scanned at the station? How does the ticket reading process work at the stations?