We're in a similar boat - I'm also returning to the hobby after 10 or so years away. It seems like a LOT has changed in the hobby during that time, but much of that is to the good. I'm excited about having jumped back in. My 32 is cycled and I'll be putting my first couple fish in quarantine as soon as I'm confident the QT is fully cycled.
You'd asked about where to get live rock - it seems to me that actually LIVE live rock is harder to get than it used to be, with many jurisdictions having banned its export. I'm sure some of the veteran folks on here can tell you more about that situation than I can. I ordered aquacultured rock from KP Aquatics and was really happy with the experience. It wasn't cheap, but it seems like good quality rock with plenty of life (including, unfortunately, at least one aiptasia that I've spotted so far) and good coralline coverage. They delivered exactly what they promised and I had no issues at all. I'd definitely recommend you check them out if you're still sourcing rock.