If you can program, you can pick up python amazingly quick and get useful stuff done almost right away. There is an impressive library of stuff available as well. But it shouldn't be absolutely required for any pi related work.
You can attach many sorts of IR receivers to a PI, from demodulating detectors (like used with TV remotes) on GPIO to somewhat specialized USB dongles and irda modules. What you use depends on what you're trying to receive. There are also less communication-oriented IR uses in e.g. PIR sensors, light beams, and raw "morse code" style flashers that are all accessible as well.
Which ever task you want to do, you should try to find a receiver that looks like a standard device of some sort to avoid having to hunt for drivers. A USB serial port type might be handy for the pi. There's a logic level UART on board (might not be avilable/easy for this) and you can get bot LL and EIA232 voltaged serial dongles for USB for more ports. These do your classic cellphone-laptop-printer style communications, not TV remote style.
For on-off signals, GPIO might be the way to go. It's harder to do fast signals with the roundabout way these are accessed in common operating systems. Accessing GPIO without breaking system security is another challenge.
How you get to these from Node, or js, is another matter. There may be a library/binding for accessing some devices. Others you can access through device files or by running some kind of middleman program (this might be a natural spot for Python) that will handle the device and that you can talk to from js.
If it all seems unfamiliar, think of this as some pointers and keywords to a lot of interesting reading :)