Yes there are ways but without knowing what you are trying to do there is no way for me to understand what would actually help you.
That said this really wouldn't be suited for the Resource manager support section as it is more of a general development question as you brought up an example of page nodes which has nothing to do with the RM.
I know that a few people made comprehensive guides for development within xf that are located in that section.
If you search within that section for an author named Fuhrmann, he has quite a few guides that are geared toward someone with no experience and can really help you gain a grasp of things. There are other guides that will get more in depth but I think following his guides first is probably the best way to get yourself going.
I just started a topic sort of asking about this, so I have the same question.
I write a lot about basketball players, and I do a good amount of in a database, including their profile information (height, school, etc). I have a number of PHP files querying and echoing that information that use in WordPress pages via 'include' (and a plugin that allows PHP coding on WP Pages and Posts. (I have actually doing it via content blocks now, which makes it easier to use some of the queries.)