sure you can get two of them, problem is as they drift relative to each other (see the datasheet it tells you there is an internal RC oscillator tuned to 5%...) you will have periods where the interrupts are landing on/near each other and the accuracy may or may not suffer, simply depends on how fast your handler ends up being.
encoders like these that output a gray code or some sort of similar code
these basically use more I/O pins but dont change state unless the encoder moves, then every so many degrees one of the pins will change you can tell from the prior state to the current state which direction that pin moved. in software you +1 or -1 a variable that is keeping count and that is your position, the datasheet tells you how many degrees per state change so you can figure counts per full rotation, etc...
Not sure about the one you chose but some of these are infinite rotation so you dont know where you started, when you start up the software has to assume or have saved the last virtual position, etc. then +/-1 per state change from there.
same deal with the one you have have to look and see if it has stops or if it is infinite, what does it define as zero degrees, does that change on each power cycle, etc. read your datasheet that is what bare metal is all about the programming is the easy part.
there are many ways to skin this cat, other encoders that work similar or different to these. at the end of the day you end up with a number that represents a position in the rotation of the dial, and then you can forward that number upstream to whomever needs it.
you could also setup a periodic interrupt based on a pi timer and sample a single gpio pin and map out high and low from that end up with the same kind of deal a high time and low time and the ratio is the position. could sample both gpio pins from both encoders per interrupt. could just circular buffer it and let the foreground code wade through the long list of ones and zeros to find the edges and the ratio. could easily use python for the forground tasks for either/any of these solutions.
I know little about linux on the pi, it supposedly has pretty good hooks into the peripherals better than some other linux/arm platforms, so dont know how to hook the gpio interrupts.
the pi-zero doesnt have ethernet as far as I know, there is a wifi one. would need to add another $15 bucks or so for a pi hat or some usb thing after buying some more stuff to get at the usb. it is a bit of overkill for this task a microcontroller is better suited, there are a number of solutions out there off hand I know about a $20 board from ti with a cortex-m4 microcontroller on it EK-TM4C1294XL but if you are asking Phython/C++ questions then maybe maybe not on that, note if you are just using this as a front end to send the current state over ethernet, udp is very easy to generate packets, you can do a lot of cheating to make a udp stack, basically answer ARP, then have the host ask you for the position every so often, using say a 64 byte packet, you steal the ip and mac address from that request and just echo it back, you can generally get away with that and not actually arp them. swap the macs swap the ips swap the ports, stick the data in, dont have to compute the checksum i fyou dont want not required with udp, and spit that packet out. easy... otherwise you are integrating someone elses full blown stack
we are in the world of IoT so there are many wireless solutions that you can get for pi prices but without the shipping or you could add one of those to a $20 microcontroller board for under 10 have everything you need and not have to learn about ethernet/networking packets/protocols let the esp8266 or whatever do that for you. I am sure there is an easy to program calling apis solution using an arduino.
the pi will work at least one of them, ethernet, you would ahve to solve you could add an esp8266 or other similar device to it to get your wireless if you dont want to deal with the pi-zero W. but if you can pull this off running linux then the network stack is right there you just use it.
blah,blah,blah just rambling now...