As you're new to Construct 2 I'd go for simple steps. Something like this:
1) Start by building a true/false quiz with 3 fixed questions to get familiar with the tools at your disposal.
2) Learn about arrays and get those 3 question/answer pairs put into a simple array.
3) Get the array to randomly select just 2 of those questions for a quiz.
4) Expand the array from 2 (true/false) to 4 (A/B/C/D) options.
5) Build a "difficulty" factor into the array so that you have a very small selection of questions at each of say 3 levels.
6) With the skills you will have developed by this point you should easily be able to increase the number of levels and expand the data in your question bank to upgrade to a fully functioning Millionaire game.