My friend and I are trying to find a way to practice as quietly as possible,because we live in an apartment with lots of people complaining. So we were wondering if it were possible to connect an electronic drum ,electric guitar and a mic in such a way that we can both listen to what we are playing with each of our headphones.We have the instruments,2 headphones and 2 amps.If this is possible what would be needed? Thank you for your time.
You have a few options depending on how much you want to spend and how you might use the equipment in the future.
The ideal product that was invented for just the scenario you described is the JamHub Bedroom available at many music specialty stores at a price of $299.99 US. It allows up to 5 musicians to plug their instruments into one of the 5 stations and dial up the desired mix for each individual instrument or microphone and each musician can plug their own headphone in. There is a picture below and a great description and link to a demo video here JamHub Bedroom at Sweetwater Music
Next best option would be a small mixer with enough inputs to accommodate your guitar, mic and drum kit and either a headphone amp or a headphone splitter.
A mixer like the Harbinger L502 pictured below will accommodate a mic, electronic drum kit and guitar and has a headphone out jack. This mixer is around $45.00 US and a very similar Behringer Xenyx 502 Mixer is about the same price.
Small format mixers with built in effects start at just over $100 US and will give you the option of adding effects such as reverb or delay if desired. If you get a mixer and hope to start playing in a band someday, you might want to be sure you get one that will accommodate your future needs as a stage mixer in addition to your silent practice solution.
Then you can plug a headphone splitter cable like the ones pictured below (very inexpensive) into the headphone jack to provide headphone monitoring for multiple headphones. Of course this option does not allow for individual volume control unless you have a headphone with a volume control.
Or for individual volume controls for each headphone, you can use a headphone amplifier like the one below.
Here is one other idea. If you think you might like to record some of your jam sessions and convert the recordings to mp3 files (perhaps so you can post on social media), you might consider using one of the headphone splitter options with a multi track recorder such as the Boss BR 800 Digital Recorder (I own one of these). The JamHub (mentioned above) also has a stereo recording output for the overall mix.
The Boss BR 800 pictured below will allow for simultaneous recording and monitoring (through the headphone jack) of up to four inputs. You don't have to be recording to monitor the input. It also allows you to over dub using up to 8 recording tracks and has tons of built in effects for guitar and vocals. Similar models by Zoom and Tasco can be found for under $300. US.
To connect multiple headphones to the single output, you need a headphone amplifier. I am using ART Headamp IV but many others exist. You can also try to use one of the available connectors like this that simply forks wires, but the sound level differs if the different headphones are connected in parallel, and cannot be adjusted individually.
To join multiple inputs into the single input for the head amplifier, you would ideally need a mixer. However you mention that you already own as much as two amplifiers - these frequently have the built-in mixer so that the different sound sources can be connected directly to the amplifier. If it is so, simply plug all sources into one of the amplifiers and connect its linear (preferred) or headphone output the amplifier to the input of the previously mentioned headphone amplifier.
Of course, you need to suppress the regular high power output of the amplifier if using it as a mixer. Look of some switch, maybe on the rear side. Of maybe the speakers will turn off automatically after you plug the (not necessarily used) cable into headphone jack.