Hi Siva,
Working for Microsoft Support does not tell us much. What product did you provide support for, and is that helpful at all for Microsoft Dynamics 365. Do you have any experience with Microsoft Dynamics 365?
Interview questions can range based on the type of position that you are looking for.
Before delving into learning development, you should probably get experience with the actual product.
I answered something similar in another post, which might help you out.
I would recommend you take an approach of learning one feature set at a time. Especially with Dynamics 365, there are a lot of integration points, which can probably wait until you have learned some of the more basic features.
I would start with the following four areas of the application:
Sales, Service, Customization and Configuration, and Deployment.
These are also 4 exams that can lead you to getting a Microsoft Dynamics MCSA and MCSE certifications.
There is plenty of training material on MBS or Microsoft Learning Portal.
You can get an educational or consultant account by using 365 Talent Portal, and then start going over the videos provided by Microsoft for the different sections:
www.365talentportal.com/.../specialized-microsoft-dynamics-training
After you have mastered these four areas of Dynamics, I would dive into the development of Dynamics 365.
There are three areas which you should focus on:
Client Api, Web Api and Server Side Development (Plugins, Actions and Custom Workflow Activities).
Take a look at the following link for information about the different sections of development:
docs.microsoft.com/.../developer-guide
Hope this helps.