[SalesForce] ExactTarget Query Activity Data View – Correct Names

The underscore (_) before the Data Extension name only applies to system-level 'Data Extensions' known as 'Data Views', such as _Subscribers, _Open, _Click, etc. For any of the Data Extensions you created in the account, you will only need the name of the Data Extension - no underscore required. Also, Data Extensions with spaces in their name should be surrounded by square brackets [ ].

With that in mind, your INNER JOIN is still a bit off. Since you are technically joining three tables (subscribers, usage, information), you will need two INNER JOINS: A -> B and B -> C. So it would look a bit more like:

FROM _subscribers a
INNER JOIN [UserData Usage] b
ON a.SubscriberKey = b.Subscriber Key
INNER JOIN
[Website Information] c
ON b.SubscriberKey = c.SubscriberKey

Lastly - relating multiple Data Extensions together through the data filters is possible when using Primary Keys and Data Relationships. Feel free to have a read through this:

https://help.marketingcloud.com/en/documentation/exacttarget/subscribers/data_extensions_and_data_relationships/data_relationships/

Lastly lastly, there aren't too many ExactTarget-specific SQL examples on this website, but I find just searching the regular Stack Exchange for general SQL help can get you through most problems.

Good luck!

First of all ask support if they enable you to access the dataviews. I believe they have to enable it for your account.

Create a data extension with these fields:

https://help.salesforce.com/articleView?id=mc_as_data_view_subscribers.htm&type=5

Create an SQL Activity:

SELECT
SubscriberID, DateUndeliverable, DateJoined, DateUnsubscribed, Domain, EmailAddress, BounceCount, SubscriberKey, SubscriberType, Status, Locale
FROM
_Subscribers

Target it to the DataExtension you just created in step 1.

The same procedure for ListSubScribers:

SELECT
AddedBy, AddMethod, CreatedDate, DateUnsubscribed, EmailAddress, ListID, ListName, ListType, Status, SubscriberID, SubscriberID, SubscriberType
FROM
_ListSubscribers

For all other dataextensions follow the same steps. Here is an overview of many dataviews https://help.salesforce.com/articleView?id=mc_as_data_views.htm&type=5