Cartography: get the osm rendering stack on your laptop and a bit of data, then map away!
Programming: get the documentation first, manuals API reference, tutorials, and use a language that doesn't have much "now install this library" dependencies.
Programming: get the documentation first, manuals API reference, tutorials, and use a language that doesn't have much "now install this library" dependencies.
DevDocs[0] (offline collection of API docs) is perfect for this.
[0]: https://devdocs.io/