Hi gmarta,
So there isn't a set "subscription centre" built into Marketo per se. You have a couple of options:
* Run the subscription centre outside of Marketo (eg. source of truth is Salesforce) and then simply sync in the different fields that you need to determine subscriber status.
* Run the subscription centre inside Marketo (eg. source of truth is Marketo itself) and utilise things like Boolean checkboxes to show subscription or unsubscription from certain communications.
If you have the option, I would recommend centralising this in CRM if you can. It just makes it easier to manage long-term. If you run it via fields and forms in Marketo, then you will need to think carefully about the impact of things such as the global unsubscribe field. If you pop this field on a form and it's checked when someone clicks to change their preferences, then it will automatically opt them out of everything.
But the short answer is - if you have simple needs, you can set up a subscription centre pretty easily in Marketo. Create a landing page, put a form on it, and have the form hold the different subscription preferences as fields (likely as boolean fields). Pop a link to that in your emails, and that should work just fine.