If someone is going all in and hoping to add a collection of lenses, it makes sense to focus all attention now and in the future on a single type - it can’t be over stressed, that not all lenses are interchangeable. Going cheap and buying an oddball camera that makes no sense to buy future lenses for is money down the drain.
When someone in the family wants to get into photography, it’s like buying a first rifle or first car - the odds of it being the one forever rifle or car are slim, but you don’t know what you don’t know up front. I buy kids a used 243 as a first centerfire rifle, knowing they will develop interests that can’t be known up front and they will probably sell it and get something else. A used Honda Civic makes a great first car, even though it’s not going to be the “one” forever car. In cameras it’s hard to go wrong with a used name brand that isn’t too old - price is good, features are good, pixels are good, lens selection is good.
Digital photos need to be adjusted - there’s no way around that. Every photo in every magazine, or on every professionally prepared website are manipulated. If you aren’t interested in doing it after the fact, your choice of camera should include the best preset settings. For years Canon photos just looked better than Nikon right off the memory card - look for comparisons between competing systems.
For use outdoors, keep in mind less expensive lens systems aren’t dust/moisture sealed as well as the ones designed for professional photographers - if your inexpensive Nikon isn’t sealed, it has to be kept in a case and babied much more. Imagine having binoculars that weren’t sealed.
Not all used lenses on eBay are jammed up with grit, but all lenses jammed up with grit eventually end up on eBay. Be careful who you buy from.
Look at battery life - inexpensive cameras are often limited to smaller batteries, while systems aimed at the advanced amateur and professional market are designed with extended range batteries in mind.
Be realistic with pixels - the absolute best resolution a handful of years ago is still pretty good, even though they look sad on the spec sheet compared to the latest models.
I love old cars, old guns and old professional grade cameras, but there is somewhat of a usability cutoff - the features of the viewfinder screen matter a lot, and a full tilt professional Canon like a war correspondent or National Geographic photographer used when digitalis first came out may be built like a BMW, but if resolution is worse than an iPhone you might not be happy. I like a big screen that can be used as a viewfinder when shooting video. Nobody told you a good digital takes great video? That’s a trade off - many new models are easy to take great video with, older models not so much. 4k video is a cutoff between old stuff and fairly new stuff.
Personally, I think a macro lens is essential - many cool things in nature are tiny. I don’t see the value in a lens that isn’t very wide on the low end and not much of a telephoto on the top end - these are the cheap lenses many cameras come with. Get something with a very wide angle, and another with a decent telephoto. A dedicated digiscope adapter would be nice, but it’s not always as simple as you’d think in this type of camera. A good photography shop is worth its weight in gold for these questions and getting something that works.
There’s nothing that will sharpen up your wildlife and landscape photos like a heavy professional tripod - now’s the time to get one for shooting off of as well as taking great bird pics.
Photography is every bit as confusing and complicated as any other hobby - keep at it and the equipment will start to make sense.