Recordings can be radio, video, mp3, CD, DVD, Blu-ray, cassette tape, LP, 8-track, ADAT, VHS, BetaMax, reel-to-reel, etc.
Playing with recordings is almost the same experience as playing with other people. It's the best preparation for playing with bands, or just jamming with other musicians. Even if you just want to play solo pieces alone, playing with recordings is one of the best ways to get better. Your ability to keep up with a recording is a measure of your abilities as a player.
How do you get comfortable playing with recordings? Start by finding just one or two things that you can play along with. Then, muster enough patience to practice playing those one or two things for a little while. Take a little time to interact, keep your expectations low. Start adding to the number of small things you can play along to. Take the time to interact. After that, you have a basic comfort level.
Once you have a comfort level, you can start to learn. Until you have a comfort level, it's hard to do anything on guitar. Getting to a comfort level doesn't take very long, and isn't physically difficult. Most of the discomfort is in the mind, and that passes quickly if you just focus on the physical task. In other words, don't overthink it.
Most of my practice is playing along with records, tracks and videos. Over the years, I've become expert at re-engineering guitar parts by ear. But it stated out with just jamming along with records, trying to play something that fit in. That led to learning real guitar parts and an understanding of how the guitar works in different styles. And that allows me to know the possibilities in any musical situation.
I still practice scales and chords separately. I've done enough work with metronomes and drum track that I have a solid sense of time. I don't need a guide just to play in time.
Playing with music is still my favorite way to practice. It turns every practice into an experiment and a physical contest. What you play on top of a song depends on what you're trying to improve. For scales, find a song at a challenging tempo, and in a key you want to work with. Then turn up, so you can hear yourself over the recording. Put the track on 'repeat,' and you're the featured guest with your favorite band.
You'll start to find things from the song on your guitar. And you get the feeling that you're retracing the thoughts of the musicians on the record - and you are. Not only retracing their thoughts, but retracing their steps because you have the conditioning, and you know the musical concepts they know.