>Are there any advantages of using a tracker instead of a daw?
This depends on what you consider an advantage.
First thing is, some people find it faster/more comfortable to write tunes in trackers, but that's entirely subjective thing. You lose the possibility to see relations between note intervals without pianoroll, one of the most helpful features pianorolls have to offer, and what makes them so immediate to use. I personally love pianorolls, but find it easier to make more unusual drum patterns/rhythms in a tracker.
Second thing is technical accuracy. Bear in mind that trackers divide into two different groups, based on how they actually generate sounds:
1. Sample-based trackers, these are like regular sampler + sequencer combo, with the sequencing part being main difference from regular tools, with its grid-based, vertical scrolling interface. You have to load your own samples into them to use them as instruments (some trackers actually support VST plugins, but that's rather rarely used, especially if you aim for chiptunes)
Examples: OpenMPT, FastTracker, MilkyTracker, SchismTracker, ScreamTracker, DigiBooster, ProTracker
2. Trackers that emulate specific sound chips, and render native formats that can drive the real hardware to make it beep boop. These are what you want to use if you're going to compose authentic chiptunes.
Examples: FamiTracker, AdlibTracker, CheeseCutter, DefleMask, SnevenTracker, Vortex Tracker, Raster Tracker
>Also are they hard to learn? What tracker would you recommend?
I can only speak for myself. Chip trackers are much more hard to learn to me than sample-based. Sample-based ones are relatively easy to start with, but hard to master, and there are quite many effect codes to remember (BTW, it's good to be comfortable with hexadecimal notation, since many trackers tend to use it for some reason that i haven't ever seen being justified).
Anyway, i'd recommend my fav (OpenMPT :p) as first tracker to play with. First thing you'll want to do though is to change the default chromatic keyboard mapping to FastTracker-like (horrible for people used to FL Studio, like me, who like to have sharps and flats above the regular white keys)
PS. Assuming you're on MS Windows, but you can run OMPT with WINE under Linux/MacOS.
Or just use Milky (uhm, don't do this actually) xD
Also, welcome to BotB, have fun!