This project is not difficult to do. Here are a few tips to get you started.
1. Start out by creating a table with the unique_id, the question, the four options, the question type (Drop Down or MCQ) and the correct answer.
2. Decide on whether the questions will be entered into the database directly or by the user using a form. If it is to be through a form then you have to create a form for putting in these questions.
3. Create the Q&A page. This can be done by looping through your db of questions and echoing the required ones along with the choices on the page, in a form
4. Create the processing script to accept the answers from point 3 and compare them to those in the DB to check the answers and calculate the score.
Start out with the code. If you get stuck, post the problem you are stuck with here. There are several of us who will hep you out and get you on your way.
All the very best.