I think Famebit has a minimum requirement of 1,000 subscribers so you won't be able to access it yet. Even then, they aren't really sponsorships. It's more like getting paid to make videos promoting a product or brand. And even with the 1,000 subscriber minimum, most of the companies are looking for channels with thousands of subscribers. Freedom also requires thousands of subscribers for sponsorships.
You can try contacting companies on your own but I doubt you will be very successful finding any sponsors unless you have like over 50,000 subscribers.