You do not need a sound card.
As others have said, you need an Audio Interface.
Never buy anything with the word Behringer on it. You've been warned.
If you want "better quality" you need to start investing in it.
Here is how Digital Audio works:
1. Microphone picks up the sound.
2. Microphone goes into a Pre-Amp, usually in an Audio Interface.
3. The interface converts Audio to Digital (and later, Digital to Audio, in AD/DA conversion)
4. The digital signal travels over USB cable to the computer.
5. The computer runs some sort of software - a "DAW" that records the incoming digital signal from the interface, and it writes that to the hard drive as you record. The computer has a "driver" (like an ASIO driver) that handles the digital signal coming in and out. People with upgrade this if theirs is sub-standard.
Now, you can just record, but ultimately, you'll want to play it back, or possibly even hear it while recording. So:
6. The Interface converts the digital audio back to analog to go out to a pair of studio monitors (speakers) and/or headphones.
Each of these steps can be a "weak link in the chain" - if any one of them is substandard, it's going to make the quality no better than that step.
So, if you use a $19.99 microphone, you can't expect to get great quality.
If your mic-pres are noisy, you'll get noisy recordings.
If the A/D conversion is sub-standard, your recordings will be too.
If your monitors are not good, you won't be able to hear if you're getting good recorded signal or not.
"Professionals" and even "Amateurs" (or "Hobbyists" if you like) do not record using 3.5 mm stereo miniplugs through the jacks built-in to the computers. Those are not designed for quality audio. Sure they sound OK, but the mics are not full range, the pre-amp is not great, A/D is not great, computer speakers are not great, and so on.
There are "budget" gear options, all the way up to professional gear options.
High end pro gear uses a PCI card that goes into a slot into your computer. They won't want to use the "stock" soundcard because it won't be good enough. But this is for really high end systems and since you're looking at really cheap Behringers, it seems unlikely you want to go that route.
You need a "decent" Microphone, a decent Interface (like the Presonus mentioned above), and decent headphones and/or studio monitors.
You're probably looking at about $150.00 USD for each item (for each speaker for the monitors) so you're looking at around $600 - $800 USD to get into a "decent" signal chain.
If you want "good", you can start thinking about spending more like $500.00 USD on each item.
A lot of people opt instead for "handheld" or "portable" recorders such as the Sony or Zoom handy recorders that record to an internal SD card that can either be removed and the files copied onto a computer or the files can be transferred over USB.
This is an easier "all in one" solution because it's something you can set on a table or mount on a stand, press record on, and play. Press stop, then record the next file or dump it to computer (where you could edit it further if you like).
Still, it would be best to have decent monitors or headphones, and running them out of the miniplug port on your computer (which apple will probably dispose of next year anyway) won't sound that great (so headphones plugged into the handy recorder would be the better option).
The advantage to the Mic - Interface - Computer - Software - Monitors/Headphones approach is that you can upgrade items individually when you can afford to.
Free software can be fine. Audacity works fine.
Headphones need not be expensive, but $120.00 headphones will sound way better and last far longer than consumer $50.00 headphones. If the headphones do not come with a 1/4" jack (or the 3.5mm to 1/4" adapter included), they're not worth your buying! Sony MDR-7502 is a bare minimum.
Studio Monitors are tough because what's best depends on the room and a lot of other factors. But you could "get by" with a Bluetooth speaker if you've got decent headphones to check your work with.
Presonus interface - $100.00 or so for the Audiobox - would be "OK".
Microphone - most crucial part for the start. This is where you should put most of your money in if you can. A Shure SM 81 will set you back about $350, and a KSM 137 about $300.
But that's really the level you need to be at - because if you can get into a mic at that level, you'll never have to upgrade those - you can get other more expensive ones later for other purposes, but these (especially the SM 81) are classic mics.
But they are cardioid condenser mics and need phantom power, which the Interface will provide.
Some less expensive mics will work "ok", and could allow you to buy a cheaper interface without phantom power, but each link of the chain you sacrifice quality on, the worse the sound is going to be.
Anything will be a step up from what you've probably done in the past, but IMHO if you can afford to, you should try to get up to "Hobbyist" level, rather than "person who keeps spending money on the wrong equipment for years and gets frustrated" level.