Generally speaking, knowing ones gear is knowing the tools' full capability, limitations and the skills/imagination to use them appropriately.

Buying a new gear, camera, lens etc. everytime a new one is advertised, may improve one's happiness and pride but do not improve the photographer, unless he/she knows that he is buying the solution to solve a shortcoming he/she has encountered and failed to solve with his old equipment.
Who knows, maybe the right purchase is a seminar of techniques?

Although it seems natural to seek the cumulative advise of the community when a one is going to face newgrounds, many fail to ask the right question about circumstances that may be present. Instead they only ask what gear to bring, because they have yet to know what each tool can achieve.

Choosing a gear to full fill what can be expected to happen, following the saying;"The right tool for the job" is more productive than bringing a gear (because of someone's recommendation which may be from a different experience) and expecting it to answer all challenges, which goes with;"If all you got is a hammer, everything is a nail".

One can only effectively choose, if they know their tools.

Having knowledge of possible circumstances, do not assure they will happen nor prevent other situations to unfold.
Even then, having the gear for those meant the best images possible for that expected moment.
And in knowing what those gear can and cannot do, then it is easier to choose a secondary/supplementary gear for other eventualities.

Cellphones' have now been really great for general documentation and would readily fill the spot of secondary/supplementary gear. Some may even choose them as their main gear for the matter.

The main gist is knowing what one wants, what one expects and what one can do to get the desired result.

It's a big world to explore; may you have the best light, beautiful moments & happy smiles!

'New' is mostly irrelevant, in terms of digital cameras. Granted, you won't have warranty support. Nor, the latest brag rights on UHH. And, the older the model, the less likely of a repair option. But, modern cameras, say anything from 2015 onward, are luxury goods. Few 'need' can interchangeable lens camera. Lower-end models compete with $1000 phones, so who needs a $1000 camera-phone and another $800 camera-camera? As luxury goods, this equipment is built for the long-haul, where 'used' is typically indistinguishable from new in the equipment's long-term useful-life-expectancy.

Since you refused to provide the requested details to give focused answers, consider the Canon Powershot models, that are all 'new', 'digital' and 'sub $800'. I shoot with an older Canon G9X-II, a 20MP model, where Canon and Sony have standardized on this pixel resolution and cropped sensor for their multiple models in this pocket-sized model. Sony's version are 'Cybershot'.

For interchangeable lens cameras, you just have to consider your options. A widely popular model like the Canon EOS 5DIII now has a glut of used models in the resale market. They're appearing lightly used in the $600 range, for a 22MP full-frame camera with many of the features of Canon's top 1DX-II model from the same 2012 time period. Any 20MP to 24MP model is much the same as another, whether new or 10+ years old. Worrying about 'new' is your own self-limiting decision, and worrying about sub $1000 is unrealistic for 2023 -- probably forever more.