To add to the point above: since youre just starting out, that sub-$1000 budget for full frame can get a bit tight once you factor in lenses. Full frame glass usually costs way more than the body itself. Honestly, the glass is what makes the image, so you dont want to blow the whole budget on just the camera body. Are you planning to mostly shoot video or are you sticking to stills? Also, do you see yourself carrying around a bulky setup or is portability a big deal for you? From a technical side, Sony has a lot of older full frame bodies that still hold up, but the autofocus on the newer ones is where the real magic happens. If you go too old to save cash, you might miss out on the real-time tracking that makes these things so user-friendly for beginners. Knowing your primary subjects would really help narrow it down tho...

For under $1000, just get the ZV-E10 II. https://www.bhphotovideo.com/c/search?Ntt=Sony+Alpha+ZVE10+Interchangeable+Mirrorless&BI=8941&KBID=10361&SID=12345&DFF=d50