I have been thinking I have to have a Mac and use something like Cubase or other to get a good recording experience. If you compare Audacity and Cubase strictly from a sound quality aspect and you are using a new computer with an i5 or better and 8 gigs of RAM…will there be a difference
in sound quality.??For recording uncomplicated music,no vocals, and maybe 10 tracks max…
The biggest difference, and the only difference that matters for Linux users, is that Audacity can run on Linux, and Cubase can’t.
No difference. Provided that the program supports at least 24-bit 44100 Hz sample rate, the application will be able to faithfully reproduce the full audio range in terms of frequency range and dynamic range.
Audacity supports up to 32-bit float, 1 MHz sample rate, which surpasses the abilities of even top of the range, professional audio hardware.
I’m not sure what the specifications are for Cubase (you are just as capable of searching their website as I am), but I’m sure it will support at least 24-bit 44100 Hz sample rate.
The biggest difference, and the only difference that matters for Linux users, is that Audacity can run on Linux, and Cubase can’t.
Your choice of recording software does not affect quality. The software simply has to capture the digital audio stream and send it to your hard drive.
“Quality” depends on the acoustic & analog-side (assuming everything is working correctly). For high-quality recording you need a good-quiet “studio”, a good microphone (with good mic positioning), and a good [u]audio interface[/u] (plus a good performance to record 
).
Note that stage/studio microphones are not compatible with regular soundcards or laptops. You need an audio interface with a proper low-impedance balanced XLR microphone input, and studio condenser mics require phantom power (supplied by the interface, mixer, or preamp).
A good “studio style” USB microphone (AKA “podcast mic”) can work too. They are super-convenient and you’ll save a little money. But, but there are some limitations. And you may not get the same quality, but some people do “professionally” record audiobooks with podcast mics, so it’s possible to get decent quality, depending on the mic and the studio setup.
For “serious recording” I wouldn’t use a regular consumer soundcard/soundchip. But, your regular soundcard/soundchip is probably OK for post-production mixing & editing. Most soundcards/soundchips have very-good playback quality (often better than human hearing) and it doesn’t directly affect the sound quality of your production, it only affects what you’re hearing.
If you plan on doing professional-level work, you’ll also need a pair of decent studio monitors, and again a “studio” with good acoustics. (Good headphones are cheaper, but the pros always advise against using headphones as your primary monitors unless you are specifically making a headphone-mix.)
Once you’re 'in the box" it’s just numbers. If you are using effects (reverb, compression, EQ, etc.) you’ll get different results with different software. (But, there’s nothing wrong with the basic sound-quality of Audacity’s supplied effects.)
I have been thinking I have to have a Mac
Most good audio hardware & software runs on Windows or Mac. Most audio interfaces don’t come with Linux drivers, but “basic” USB soundcards & interfaces are class compliant and they will work with Windows, Mac, or Linux. There’s nothing wrong with using a good-basic audio interface but if you’re getting a high-end multi-channel interface, you’ll need to make sure it works with your operating system.
and maybe 10 tracks max…
If you are multi-track recording more than 2 tracks/channels simultaneously you’ll need to make sure your multi-channel audio interface works with your operating system and you are better-off with Cubase or some other “real” [u]DAW[/u]. Audacity can mix multiple tracks, but you’ll probably find a DAW more convenient (once you get past the learning curve). Cakewalk is now FREE, so it’s probably worth trying (if you have a Windows system).
Main thing for me is I don’t believe you can use VST instruments Audacity.
That would mean no Arturia synths and keys, and no EZ drummer VSTs. Bummer