$500 budget - what to do?

create a landing page and start affiliate.... you can make money using your $500

You can do a lot of things, One idea is to start doing CPA+Youtube for example at first you will learn how to rank your videos and at the mean time learn about google ads that way you can make a lot of cash mate keep in mind! 500$ Is ideal for CPA and ADS

You can invest into Adsence or SEO works, it will make you a profit several hundreds %