A non-accredited crowdfunding platform typically won't require you to meet any specific income requirements. However, you will most likely need to make a minimum investment --- usually somewhere between $500 and $5,000.
Accredited investing is a whole different beast. To do this, you need to earn a high amount ($200,000 for individuals, $300,000 for couples) or have over $1 million in net worth (more on that above). Most people can't afford accredited investment opportunities.