Where are the mysql tables where "custom field" data is stored – how to query "custom

Hi, I am absolute new to WPMU DEV and bought a membership mainly because of the “CustomPress” plugin (of which I thought would be a Theme! – guess, I did not read all the information carefully enough and still lack some understanding of the English language). To me the “examples” are a bit misleading for it is mentioned CustomPress is suited for building a “movies database” or referring to “book database”. Me naive, have already promised a client to “program” a real-estate application for him (having your showcase “RealEstate – CustomPress” example in mind) – with WordPress as foundation, silly me! Long story short, I cant find any information of this plugin that relates to data storage,not to mention data retrival! Not even some basic data search functionality seems to be available with this plugin – you are mentioning a “real-estate” application that “heavily relies on the CustomPress” plugin and use this as an example of the capabillity…? Wow, thought, most of the search functionality of this real-estate site would had been done with the CustomPress plugin?! So now I am not only frustrated, I also can not find any information where the data of “custom fields” for exmaple are stored, so I could get my hands on them… Do I have to start coding with bare PHP and MYSQL and forget all about the easy to use plugin stuff? Please give me a hint!