Android headset connectors/adapters for a wired headset, what do I need? I need to get a wired (not bluetooth) headset for my LG Aristo 2 Plus, but I don't know what I need to make it work.

I imagine there are only two components I need to worry about: (1) type of connector on headset and (2) type of connector on adapter. Adapter may not be necessary, but probably is for wired headsets.

I've wasted a lot of money on adapters to make a cheap wired Plantronics headset work on my old work iPhone, but none of them worked. Maybe Android-based devices are easier?

To be clear, I need a headset for talking on the phone, not a pair of headphones.

Any nudge in the right direction would be greatly appreciated! If there is a canonical answer out there somewhere, please point me to it.
Android has two standards OMTP and CTIA/AHJ, whether it is a headset only or a headset with built in mic. Details in answer Why external microphone doesnt work on some Androids (like LG G5) (this likely covers the issue you had with iPhone) 


OMTP is practically extinct and all headphones with or without mic are CTIA. This distinction is useful to know just in case you decide to buy an accessory that follows older standard. For all practical purposes, just check it has three black rings - see picture (OMTP comes with two rings r(without mic) and three (with mic) but practically all headsets or earphones have switched to latter standard) 
Coming to the device side, 3.5mm port into which the headset is plugged is being phased out by manufacturers (regrettably) in favor of USB - Type C. Luckily for you, your device has 3.5mm jack (device specs linked by you) , so you needn't bother with an adapter. 


In case, you have a phone with only USB port, you would need to buy an adapter like in the picture below. 



(Click to enlarge) 


Lower end accessories have only one button that can be used for connect/pause/end call. Others have more buttons for media playback like next track, skip etc.
In case you buy a Bluetooth enabled accessory, the first two points are irrelevant.


tl:dr; You can buy any headset that meets your budget. Just make sure it has 3 black rings and released in last three years or so. It's a good idea to check out your device forums on XDA or other sites for recommendations if you are an audiophile. In case of doubt, check with seller or in reviews if it is compatible with smartphone