Tracktion 7 is an older version which is now free. It came out in 2016; Waveform 9 (newest version) came out in March.
I didn't check, but I'm fairly positive it's not open source.
https://www.tracktion.com/products/waveform
You'll see a comparison. Says Ubuntu 16.04 is supported, but perhaps it will install on 18.04.
LMMS is probably your best bet for simple midi recording/sequencing. Waveform Free is good if your friend ever needs to record audio as well.
First try Waveform Free. It's very easy to use and is ridiculously full featured for a free download. There is very little that is only available in the full price version of Waveform and none of that should negatively affect doing VO.
Failing that, try Reaper. It has a very poor UI with a stupid amount of menus, but if you can get past that, it has excellent wave editing features and it only costs $60 if you make less than $20,000 per year.
For clarity, I use Adobe Audition for audio editing. For music I currently use Presonus Studio One, but have been around most of the DAWs.
Another thing worth mentioning, if you like free software is available at Tracktion's website. They are an interesting company in that the version two revs back is available for free.
It's not demoware either. You have the full app's capability and unlimited tracks, etc.
"Studio One Professional 2019" ...is not a product that exists.
Ebay is not great for "going after people" who aren't legit. You will not have saved any money if you pay for a cracked account that gets recovered by its original owner in a week.
The Tracktion Waveform Free advice was good.
If you are determined to use Studio One Professional but are on a tight budget wait for a sale. It goes up to 50% off, and you can sometimes do even better at legit sites like audiodeluxe when they let you use a coupon on top of the sale price.
Glitches in Adobe Audition make no sense. I would expect that it's because of your soundcard driver, so see if there's a newer one available.
Reaper is very difficult to use for a beginner.
You'd be better off using [https://www.tracktion.com/products/waveform-free](Waveform Free was released about two weeks ago).
since your into audio stuff, may want to check out the newly released tracktion waveform pro. really legit free DAW with linux support (closed source)