I need to raise funds to purchase a laptop
Well, whatever you do, DON'T use this as your reason for attracting sponsors. You want to approach sponsors with value YOU offer THEM, outside of just views or whatever.
I'm looking into getting sponsors and such at the moment, but you really want to make sure the sponsor fits with your brand and type of content.
The BIGGEST tip I have for you though, is don't just accept any ol sponsorship offer, especially if it comes through email. Sponsorship offers via emails from small companies you've never heard of is the number one way to get your channel stolen off you by scammers, especially if they're offering you a sponsorship deal in return for you reviewing one of their programs. The moment you install their program to "Review" they will have access to stealing your channel, so be very careful.
Social Bluebook can be a good way to see your value, and then approaching sponsors you trust with a value proposition.
But for the love of god, don't go in saying "I want a new laptop, can you pay me (insert dollar amount here) to sponsor a video"