As someone with experience with recording music, if you want a free program go ahead and use Audacity. It will get you by fine for recording with a microphone, but it's not so good with organizing clips. If you want to be a bit more serious and more 'professional' use a proper DAW such as FL Studio (Windows and there is a wrapped version for Mac, idk when the proper version for mac is coming out) , Ableton Live (PC & Mac), Logic (only Mac),
etc. Just remember these can make a dent in your wallet. If you have the Mac but not any money, Garage Band will be a fine set-up, then it would be really easy to switch to Logic as they are both made by Apple. Then for microphones you have 2 (common) options, XLR and USB. I recommend USB for beginners as you do not need an audio interface. Out of microphones that are good prices I would recommend something along the lines of a Blue Yeti,
Audio-Technica AT2020, something along those lines. You will then need a pop filter, they're pretty cheap and you can just order one along with your microphone so I won't go into them. Now that you have all of this stuff you should learn to mix all of your tracks down so it doesn't sound muddy or tinny, and to do this you need decent headphones or speakers. You don't need monitors right off of the bat so most gaming headsets will have okay enough quality for now. You must also practice a lot, try new things, etc. to get the hang of everything. Hope all of this helps 
