General Question $$$

how many visitors(traffic) do you need to your website(landingpage) to at least make 500$ a week

1 could do it. If you had a landing page selling websites for $500, then you'd need to call 1 business that needs a website, then send them to your landing page. Once a week of course to generate $500 per week.

If you had a CPA offer that pays $50 then you'd need 10 hits at 100% conversion.

$5 offer then 100 hits at 100% conversion.

$5 offer then 1000 hits at 10% conversion.

What a broad question...

Based on my adsense earnings (i have VERY low CPC) you will need 100k visitors / week to your site to make that amount.
Based on my CPA earnings (again - low EPC) - you will need 5k that click on your CPA offer link.
But basically it all depends on what kind of site you have....if it is a shit site you make shit...if it's quality you can bank