If you are looking for simulation, lfs was quite doable with a mouse (https://www.lfs.net/), probably possible in most sim. If you want something with realistic physics but more fun, arcady gameplay: beam NG is probably a good one. Since you are referring to borderlands, i guess you are looking for a bit more arcade style, far cry 5 was decent in its driving fun, not sure you can mouse steer though. GTA V is quite good too.
I would suggest you start with lfs though, fairly cheap, and really good one you get the hang of it. Surely if you like it, you'll fall in the sim racing love, and you'll have to find funds to buy or make your own wheel :-).
Enjoy!