The season pass should be available for purchase on the Xbox Store. However, if you are referring to a physical version, there is none available as it is a digital entitlement.
@SithKermit, if your menu is showing some options as locked, this means that the game is downloading more content in the background. Can you confirm if this is the issue?
@Khesanh1, I believe this will be the same issue for you. Please leave the game on the main menu while the content installs.
@MasterOogwayKFP, If your internet is affected at certain times throughout the day, I would suggest contacting your ISP for more information, as there could be a throttle on your connection.
Can you please try the connectivity troubleshooting steps in the FAQ here.
If this does not resolve your issue, can you please create a case on the support website with images of the ports forwarded so we can look into this for you?