Edit: have we hugged it to death? I can initiate a connection but never get a login prompt.
Think Pascal was the easiest way for me to get started. It fits well on the screen. I use resedit to do resources and then you just link the resedit file in the project preferences. The book Macintosh Pascal Programming Primer is pretty good for learning how to start.
Think Reference is useful too, or ObiWan for an online reference.
If you prefer C, it's a little idiosyncratic on the Mac. Code warrior, older versions, will run, and so will Think C. There was also Symantec C++ for the Mac that I never tried.
If you want the apple tools, they were released on CDs called ETO in the latter years. MPW is ... well it gives you a shell but it's got a learning curve.
You can also cross compile to the Mac with Free Pascal. There's also a Modula-2 system called MacMETH. Microsoft had a version of Visual C++ that had a Mac compiler too. Sometimes the easiest thing is to set up an appletalk share and do your coding on a familiar machine with a large monitor.
The ETO and CodeWarrior CDs had Inside Macintosh in electronic format.
A lot of stuff is available on the Macintosh Garden.
There are some really good Retro68 code examples out there as well. I started compiling a list here, including a couple of my own: https://henlin.net/2021/12/21/Cool-Retro68-projects/
As a few other folks have said, the inside Macintosh books are extremely valuable references for Mac-specific code. I keep pdfs of them open the whole time I’m working on my Macintosh projects.