If all goes smoothly, will be getting a new 16" MBP. I assume they come installed with Catalina.
On setup, is there anything I should be careful about? Any definite things to stay away from?
I am not migrating anything. Starting this thing brand new and installing everything manually and connecting to all online services like iCloud.
Just did exactly this. Waited for Hazel compatibility, and kept my previous MBP on hand while I tested VueScan and ExactScan Pro for my ScanSnap scanner. VueScan was a quick no for me, but I just purchased ExactScan Pro after a trial for about a week. I also had to upgrade Parallels and Quickbooks for Mac Desktop. Very happy so far as I continue to take advantage of the extended holiday return period. Meanwhile, I nuke and paved my 13" MBP which was giving me a lot of beachballs, now that I am comfortable and invested in Catalina. FWIW, the 16" is super solid for me, and also super gigantic compared to the 13".
I also started my new MacAir from scratch installing everything by hand, no migration. I also worried about Hazel but so far my biggest issues have been printing and DRM removal on Kindle books. On the printing issue the thing we are waiting on now is a brand new printer, see my printing thread for updates. On the kindle books I have not et gotten that one worked out, still crunching through the checklist of possible potential solutions I’ve been given from both here and generally on the 'net. So far nothing has worked but I’m less than halfway down my list of potential fixes so I am still hopeful
Oh, I should add, be mindful of the many permissions apps will ask for. Many of them will open to the specific system preference it wants/needs you to accept, which makes it very easy: just unlock and enter password if needed and check the box. I few times, I went too fast with overlapping preference requirements so I had to manually go through each one and find them.