It is actually pretty simple, once you’ve got the hang of it. I use GarageBand on my iPhone as the DAW. The Interface is then simply a way of getting the signal from your bass into the DAW, i.e. you plug the bass into the interface, then the interface into (in my case) the iPhone, hit record and your away. (OK, you need to set levels to ensure your not ‘clipping’, i.e. distorting the recorded track, and you need to ensure that the interface is recording on the right channel in the DAW, but that’s just a case of flicking a digital switch). A good, and relatively cheap, interface is a Focusrite Scarlett Solo. In the UK, where I am, you can get a second hand 3rd gen one for £50. Then you just need some cables - bass to interface (guitar lead) and one to link the interface with the device with your DAW on it. Oh, and you might want headphones so you can hear yourself.
There are some pretty detailed instructions here: