Run away from the 2019 laptop. The 2016-2020 Intel Macs with USB-C ports are nothing but trouble with all sorts of design & manufacturing flaws. Plus they are the past for Apple and many third party software developers.
You must be very careful when purchasing a used Mac these days. You need to make sure you are purchasing it from a reputable seller who has properly prepared it for sale by following these Apple instructions:
What to do before you sell, give away, trade in, or recycle your Mac - Apple Support
Even if the seller has done all those steps, I would still strongly suggest you perform your own clean install of macOS by starting at Step #6 in those directions to erase & reinstall macOS. Doing so may reveal whether a previous owner is still managing the used Mac. If the previous owner is still managing the laptop, then there is nothing you can do about it...the laptop is not under your full control. This forum is full of posts where users were scammed by the sellers so it is best to stick with a seller that is known to properly prepare their used Macs and has a great return policy if you are dissatisfied.
You should check to see if Apple is selling any refurbished M-series laptops (you get an Apple warranty I believe). Another possibility is whether OWC has any used M-series Macs available.
Another danger of buying a used Mac is if you end up having it locked where you cannot unlock it. If that happens, then you will be out of luck because you won't have the necessary proof of purchase to have Apple unlock it for you (a official refurb direct from Apple is the only one that would give you that peace of mind).
What does that third party hardware & software have for recommended system requirements? How much memory and how much storage space is needed for everything? How much storage space do you need for your music files? You cannot upgrade the memory or internal storage of any of these Macs so make sure you get a computer that has sufficient memory & storage for today and for at least 5 years. You can add external storage if more storage is needed if you don't mind carrying around & connecting the external drive.
Depending on how much internal storage you need....have you considered a new M2 MBAir direct from Apple which is selling for $1,000US (MBAir 13" M2 with 16GB of memory and 256GB SSD)...not sure how that actually converts for your region though.
If you personally know the seller, then that M1 may be fine as long as they follow the instructions in the Apple article I linked. Again, just make sure the third party hardware & software you want to use are fully compatible and the system meets or exceeds the recommended requirements for those items.