Using Home and Business what category should I add venue and vendor expenses?

For my business I pay for a venue and a guest speaker to come speak at there. I collect all of the funds then pay both parties.

 

For example, I may collect 10,000. Pay the venue 4K, the speaker 5K, and take a 1K profit. For my taxes I need to pay tax on my 1K, not the full 10K. I thought I would simply expense all of the 9K? I’m new to this… Any help is appreciated. 

Thank you!