An Oracle ASSEMBLY

If the typical use pattern is to page through all the data, then all the records will eventually need to be sent to the client. In this scenario re-querying the database for every page is in-efficient. You should consider running the query once and paging through a cache on the client side.

If on the other hand the typical use pattern is to page through a very small amount of the data, then this method may be appropriate. Nick Chammas' comment on using ROW_NUMBER() is fleshed out by Tom Kyte in a Oracle Magazine article.

SELECT * FROM (
   SELECT /*+ first_rows(25) */
      your_columns,
      Row_Number() Over (Order By something unique) rn
   FROM your_tables 
   )
WHERE rn BETWEEN :n AND :m 
ORDER BY rn;

I recommend you read the whole article. Note in particular the warning to sort by something unique so that the results are consistent between pages (given static data):

You need to order by something unique for these pagination queries, so that ROW_NUMBER is assigned deterministically to the rows each and every time.

If you're really only looking to learn about the development side and have no interest in the administration or installation side at the moment, a quicker route might be to download a prebuilt developer VM image for Virtualbox. That can get you up and running very quickly, and you can connect to the DB running inside the VM from outside, so you can continue to do your development in your current environment.

The overview echos what others have said about licensing kicking in once you ship an application (but Oracle licensing is a quagmire, you'll need to talk to Oracle about it if/when you get past playing around):

Learning your way around a new software stack is challenging enough without having to spend multiple cycles on the install process. Instead, we have packaged such stacks into pre-built Oracle VM VirtualBox appliances that you can download, install, and experience as a single unit. Just downloaded/assemble the files, import into VirtualBox (available for free), import, and go (but not for production use or redistribution)!

For experimenting it's ideal, in my experience. Of course, it's unsupported, but as you won't have a support contract anyway that's a bit of a moot point.

As David said, PL/SQL is integral to the database, not a separate component, so it is available in the VM image. You get some tools too, including SQL Developer, but you might have less friction running that natively and connecting it to the DB in the VM.