There is no quick and easy way to build interactive and self-grading quizzes for a teaching site: even with a template it's a tedious and labor-intensive process. A quiz of just twenty questions could take hours to construct because each answer must yield a response, whether positive or negative, if the user/student is to stay engaged.
Ideally one would begin with a template, but those are expensive to develop and therefore tied up in proprietary issues. Starting from scratch with Google Forms or Adobe Webforms means settling for an unprofessional look since the customizing options for each are limited. Without an understanding of code or a passable fluency in techniques and possibilities, the result will look as inexpensive (read cheap) as it really is.
In order to get noticed then, in the very crowded world of online education apps. one must really splurge on a well-designed UI and template with significant potential for interactive features-- students will naturally gravitate to the sites with the best designs and graphics--and then put in some serious hours tweaking the entering and tweaking the content.