Remember that the interview is not only about cracking the case.
1) First you need to secure your interview invite. For that, you need to work on your application (CV and Cover Letter - you can have them both checked by a professional) and you can network and have a referral.
2) Your company might have a test to check your problem solving skills and logical thinking
3) Fit part interview: Behavioral questions can be:
Why consulting? / Why company XX? / Why are you the perfect fit for this position?
Describe a time when you disagreed with a team member
Tell me about your biggest mistake at workplace
Name three improvements you made in your most recent position
Entrepreneural drive stories
You can find other questions online, just pick some of them and start answering them in a way that makes sense:
Keep it short (1.5 minutes max)
Use storytelling techniques (Structure your speech!)
Try to get the interviewer to participate, e.g. while telling about your experience in place XX, ask them whether he has been there
The more questions you practice, the easier it becomes for you to come up with a nice and suitable answer.
4) Case part: Here is a good preplounge article on case solving:
Start by studying this one but don't waste your time studying plain theory, because case solving is all about PRACTICE.
Here are some cases you might wanna check out:
For Beginner level:
Laundry Chain - Revenue Increase
Launching Caskets in North Africa
For Intermediate level:
Grain Co-operative – Brand Launch
Case with a twist: Chinese Alloy Wheels – US Market Entry
I suggest you start with the intermediate level after you are confident with the beginner ones.
Hope it was helpful! Feel free to contact me if you have any questions, I am happy to help.