I still have my first road bike and still love it. A used one from ebay, but I read a lot of stuff about groupsets and bike fitting and had a more experienced friend with me when I bought it.
500 bugs for a no-name aluminum frame with a full ultegra 6600 groupset, which was already some years out of date when I bought it, but nevertheless an excellent group set. No name alu wheels with rimbrakes. Parts were still available, but now the market thins out a bit.

I would recommend anyone to buy used. It's about half the price, not much lost if you choose to resell it again, and you get tons of bikes now from all the people that started in corona but lost interest. Also, it's much more encouraging to do your own maintenance stuff on a bike that already is out of warranty.

I'd look for the groupset. shimano 105 is excellent, it is the cheapest of the serious ones (there is also shimano sora, but that's still pretty new). Rim brakes are to prefer over lower priced disk brakes, since the technology for road bike disk brakes is still new and has a bunch of issues even on the top level. All the big branches don't really sell crap (ok, they do, but on a high level), and sometimes you have cycling discounters that have some really great house-labels like in germany rose for example.