It really depends on what you’re looking for. Are you just looking to learn how to print new materials, or do you have specific requirements for a project?

If it’s the former, I’d say the easiest thing to try is PETG. It prints pretty reasonably on most printers though has stringing issues. It has different mechanical properties that make it suitable for other applications (for example, better temperature resistance and impact strength). It’ll be much less frustrating than trying to dial in ABS for the first time.

ABS and TPU are both a pretty large step up in difficulty, but are quite good for functional parts. If you insist on learning one of these, pick whichever one fits with your projects better. For ABS you’ll want an enclosure and a well ventilated room (IMO I wouldn’t be in the same room as the printer) as it emits harmful chemicals during printing.

A filament dryer was honestly the single biggest improvement to my printer’s quality. I’d definitely recommend getting one. Wet filament is so frustrating to print.

I’ve used eBay, /r/photomarket, and MPB for buying second hand gear. If you’re using any BST platform like photomarket, make sure you use a payment method with buyer protection, and regardless I’d make sure to fully test and inspect the lens upon receiving it.

A friend of mine has bought cameras and lenses off Facebook Marketplace, but sorting through the scams to find a real listing can be really annoying. I’ve never bothered with it myself.

Same thing here. I went with Sony because of how expansive the E-mount lineup was, including 3rd parties (even the lesser known ones like Samyang and Viltrox).

At the time, Canon’s first party lineup was pretty lackluster if you weren’t looking for the L-series professional lenses. It’s gotten better since then, but in terms of value it’s very hard to compete with Sony since third parties are much cheaper, and used availability is much better due to the age of the system.

I’d also recommend seeing how the USB protocol for your camera works. On mine (Sony A7R III) there are some relatively impactful limitations. One is that you seemingly can’t shoot a burst directly over USB, but you can work around this with a shutter release cable. The other is that you can’t change shutter speeds and ISOs super quickly, you can only increment/decrement them. The latter issue is fixed on newer models though.

I haven’t done this exact type of thing but my understanding is that the radios and wireless chipsets of most cameras are pretty poor in comparison to what you can get with a phone or computer. USB tethering is probably the way to go to reduce bottlenecks. You could potentially tether to a phone (though idk what the software situation looks like) or possibly an ARM SBC, as some have LTE and 5g compatibility.

I don’t have experience with the Fuji system but I would make sure you’re appropriately budgeting for lenses. The common saying is “date the body, marry the lens,” meaning spend more on getting good lenses than the body. You can hold onto good lenses for a long time and upgrade the body as needed, and good lenses can get super expensive, especially in wildlife.

The kit lens won’t give you enough reach for most wildlife, and it’s probably not the sharpest either.

I’ve tried Overture, Creality, and Inland (all black though, not transparent) and Overture printed the best for me (at least for functional parts where I cared about print quality and tolerances). Inland’s PETG+ and High Speed PETG was even better though.