So a friend of mine bought this old PC for office work and her Zoom lessons. This one has the latest Windows 10 Pro 64 bit with 3gb of RAM, Intel GMA GPU and a slow 200gb HDD. So I've told her to get a cheap 15$ ssd and I'll probably install for her the Enterprise version . The point is which one is the most "lightweight" I've been thinking that LTSC 32 bit might be too heavy and I should try older versions .
There is hardly a noticeable difference in performance or "weight" between the different SKUs, but the more current the build, the more resources it probably uses, maybe better run 2016 LTSB on it (not because of the LTSB but it's the oldest supported and properly working win 10 available (not counting 2015 LTSB, that one was not that good)).
I can already tell you this is gonna be a bad experience. My suggestion would be downloading a clean windows 8.1 update 3 iso, downloading all the updates with WHDownloader and integrating them into the install.wim with WHD-W81UI.
I run a rp5700 with a E7600 for testing stuff and there is no issue with Windows 10 64 bit at all. The SSD swap makes that old CPU feel half way decent. GMA is probably GMA 3000 for a PC from that generation and I think will be OK with Zoom.
I have Windows 10 Pro x64 version 2004 on Core 2 Duo E4600 with 4 GB ram and GPU with 512MB ram and still is fast and good with ssd from 20$.
I have installed windows 10 LSTB 2016 on plenty core2duo cpu for secretaries and similar, I think the worst I saw was a gma 950, never had any issue, although I wouldn't recommend it for anything else than actual office work.