Part of my practice regimen is to play extemporaneously – that is, just by ear- over a backing track, and here’s an example of that. Andy Usher’s tracks are just excellent for this kind of thing, and if money’s tight, he has lots of quality tracks that are available for free. You can hear his stuff on YouTube, Patreon and BandCamp. here’s his site: https://www.andyusher.com/ausher-tracks
If you’re interested in playing blues guitar, just reach out! First lesson’s free.