How do I get surveys on my site?[NEED HELP]

Hello!

I've been thinking of making a site like tremorgames, where people can come and do surveys and get keys for their games. I've learned a plenty about keyword research and SEO on this site and finally have the confidence to set up my own website. But the thing is, how do I get surveys on my website and fit them with a virtual currency tag?

I.e,
I want the visitors to complete surveys and rack up credits on my site. After which they get to redeem stuff.

Also, is this very vulnerable to malicious hack attempts?

This seems like a very complex task to complete for someone who doesn't even know what a content locker is.
Do you by any chance know how to design and program/script websites in languages like html, javasript and php?