The interview is very basic and you won’t really be asked anything that is outside of the DS-160 form that you would have filled during the application process. The general tone of the interview is around your study program and why you chose it.
The consular simply wants to know why you chose a particular university/organization based on the options and considerations you had available to you. There are some cases where they may ask leading questions like, “What will you do if your visa is rejected?”. In such situations it’s always best to give an honest answer. The consular wants to ensure that you will come back to your home country after your study program.
In addition to asking you questions they may also ask to see some of your documents. For example they might ask for your financials as proof of solvency for your study program expenses. Make sure you have all pertinent documents on hand.