This can be due to a few things, but the most common reason is that you have not completed Server Onboarding. The next likely reason is that you are not verified on the server.
Check your roles. Completing Onboarding will provide the `Member` role, and after you have verified your account, you will have the `Verified` role.
If the `Member` role is missing, complete the Onboarding process. To go through Onboarding follow these steps:
Go to the Channels and Roles menu in the Discord Server and answer all the questions.
You must choose one of the following options for the 'Member' Role, and for access to the Marketplace you must choose an option with Marketplace.
The other questions are optional and will give extra channels depending on which hobby you want to discuss, and which community channels you are interested in.
If you have both roles and want to edit which channels you follow you can also go to the Browse Channels Tab in the Channels and Roles page to choose from a list of all the available channels.