American trying to buy a ticket to the October 19th Match against West Ham.

I am in the area for business and was hoping to go to a Tottenham match. It seems like I have to become a member to be able to buy a single match ticket. Is this the case?

Is there a Ticketmaster type of website where I can buy aftermarket tickets? Is there someone on here who has season tickets or something that I could buy one from?

Any advice is appreciated!

Thanks!