how can i connect my apple tv to wifi in a hotel room

Yyou didn't say what generation ATV you have, but generally go to Settings, then Network. You should see all available Wi-Fi networks. Choose the hotel one and enter the password (you might need to call the front desk).

you may need to check with the hotel customer service to ensure that a device like the AppleTV is able to connect to their wireless. In some hotels in the past, AppleTV's were hit or miss based on the hotels provisioning.

Most hotels require login via webpage, this is not possible on the ATV as there is no browser. You would need to contact the provider or the front desk to see about gaining access to the network