I also set up my first home server with RAID NAS. It's on my list to spin up an OpenOffice container or something I can use to replace Google Sheets. That will let me delete my Drive data; next is Google Photos and eventually Gmail.
Drive was easy enough to download everything off, but the real pain in the arse was Google Photos. I had something like 250 individual 2GB zip files and the supplementary metadata was separated off of the image files themselves. I had to put together some Python scripts to clean up all the different file naming formats over the years (PIXL_YYYYMMDD, IMG_YYYYMMDD) into just YYYYMMDDD, and reattach the metadata, and then check through that everything was safely downloaded before deleting the Google Photos.
Google Photos had some weird caching issues where it kept showing images I'd deleted and emptied from the bin, which was a little concerning. They were only appearing on my phone and persisted multiple times after clearing the cache. I couldn't find them anywhere in the phones internal storage.