Hi,
Quite complex question here, but I'll try to give you some hints:
For Data Architect, you should master Data modelisation, so how to use Data Connection, resolve anomalies like Synth keys, how to use Where Exists (for QVD optimized load), Keep, Join, Concat, ect.
Manage Subset ratio and Density, Mapping load, ect.
For System Administrator, you need to know core concetp about Security Rules and Custom properties, Authentication and Authorization, Load Balancing, Qlik Services and components, how to deploy a serveur, sizing, etc.
Main of my knowledge comes from praticing during my differents missions. But you can learn it from community, documenation, and try and fail approch. I think you can define usecase, and try to implements them.
Kind regards
From MPC (and Next Decision) with love
