I’ve always kinda hated digital recording. Dealing with the software can suck the soul out of the thing for me, to varying extents. Digital has all sorts of advantages, but there’s an immediacy and simplicity to cassette that’s quite freeing. And as has been mentioned, after recording on a cassette multitracker, you really understand what the software is emulating when you do work on a computer.
That said, I haven’t had a cassette multitracker since mine blew up in a power-related incident (during overseas travel) years ago. So, I don’t know about the availability of suitable cassettes issue others have brought up. Still, as you say, it’s just for your personal use, so I wouldn’t stress too much about having the perfect matching cassette, though I’m sure some will disagree with that kind of approach.
Anyway, computer-based recording can be a whole rabbit hole. I sometimes think about going back to cassette myself, at least for some situations. I just find hooking things up to the computer to be something I’ve come to dread a bit. YMMV.
As has been mentioned, a Zoom H4N or one of their newer models can be a good all-in-one portable digital recorder. You can hook up other mics to it if you want, or for convenience, just use it’s onboard mics (or instrument/line in, with no amp), and then later you can export it to a computer for sharing or, if desired, additional editing/mixing/production.
Or, you can use your phone with something like an iRig (that might be a good approach to look into. Much like using an H4N, but with the convenience and familiarity of your phone’s large touchscreen display/interface, and with even easier access to advanced editing and/or sharing if desired. You can add a stereo mic attachment to at least one of them so that there’s always a mic onboard, though generally they’re set up for Instrument In [plug your bass into it] or use with external mics). Here’s a link to the iRig Pro audio interfaces from IK Multimedia:
https://www.ikmultimedia.com/products/?S1=553&S2=555 I’ve used the basic iRig Pro with my phone and it worked well. Anyway, I’m not claiming this is the ultimate answer, just putting it out there as an option.
Best of luck with recording, however you decide to proceed
