Seasoned dev with decades of coding experience thrown into WordPress - what do I need to know?

Hi.

I've picked up a new client who's hosted at GoDaddy using WordPress. I have several decades of web coding under my belt; I haven't touched WP in many years.

Can you point me toward some resources for experienced coders who are inexperienced with WordPress?

TIA.

Blue

Edit: I've been building websites mainly for a major public institution. Most of my experience is with php and JavaScript, and I've dabbled with many other languages and techniques.

To clarify: I'm not coding WordPress (yet if ever). I'm just managing the site. Most of the tutorials I've come across are aimed at folks with no web experience at all, and I'm a bit underwhelmed.

EDIT 2: Wow, thanks everyone! There's some sound advice and useful wisdom here. I really appreciate your thoughtful and useful responses.

And thanks to everyone who validated that it's possible to have deep experience in the field and not having experience with one of the gazzillion tools and techniques that are out there.

As an aside: a few years after I got into this field, the browser wars happened. Things got really messy for awhile. We had to deal with variations in browsers that were pretty confusing. New tools were rising that were helpful. But it was a hard time to know whether any path was a good one. I assumed things would get simpler with time. But they didn't. Web development is much more complex now than ever. Not so much in terms of code, but in the vast array of tools, options, techniques, vendors and so on. It's an exciting time, but also one of peril and pressure. Burnout is real. It has specific symptoms. Take care of yourselves. Be kind to yourself. Get some rest. Hang in there.

Thanks again for your help, I appreciate it.

Respect.