Question’s hardly dumb and I appreciate your asking for support in advance. Thanks.
Folks have worked around it–AllisonW gets OK results for JSON work via hacking her local JSONs, testing, then copying the changes to her web repo, proofreading there, and PRing–but yeah, a local repo greatly facilitates testing.
Understood re lousy net connection though. 
The XP problem is the Windows GUI, not the bash console–I hope, since I use XP too! Means you’ll have a tougher learning curve, but we’re here to help.
I’m fond of the Code::Blocks IDE and MinGW32/GCC/wev built into it, but that’s me. MinGW-w64 is more robust and we should probably migrate there at some point, but for now C::B is workable. Other devs use Cygwin, clang, and even MSVC++. On windows, we strongly recommend Notepad++ for the actual code-handling. (Settings->Preferences->Language & Tabs-> set to 2 or 4 and replaced by spaces, please–tab characters are hell on formatting.)
And welcome to the forums.