At a high-level you should demonstarate 2 things during the interview:
- Problem-solving - be able to deep dive into a problem and understand root-cause
- Structured communication - be able to explain things easily, result-oriented, matured in terms of physical presence (use hands while talking, eye contact)
Nobody expects specialised knowledge in case you come from non-business related program. You should know the basics: how businesses work and which business model is used in different industries. This will help you a lot during the case interview.
To boost your business accumen you can use the following resources:
Wharton casebook 2010- you can check how all industries work there (airlines,
Case-in-point – you can check what frameworks exist, try to practice and learn
them (product launch, M&A etc.) - pages 36-38
Web-sites of consulting companies: BCG, McKinsey and Bain - check them to gain some industry insights and deep dive into specific industry
Those resources would be sufficeient to be well-prepared for your interviews.