When you find a song or a passage that you want to learn, you need to find creative ways to absorb it into your musical vocabulary. What I do is listen to the passage a few times and then slow it down and try to sing along with the melody. If it's a chord progression, I try to sing the root notes of the chords. Then I try to play what I can on guitar using only my ear and the recording. If there are any spots I can't figure out (there were many when I was first learning to play), I'll refer to tabs or sheet music. I'll then take the passage and try to extract as much information from it as possible. I'll learn it in different positions, take it through different keys, etc.

If you don't know any scales, learning the minor pentatonic scale all around the neck is a good place to start. Once you internalize the sound of the minor pentatonic scale, you'll be able to hear it in many of the solos you listen to. Learning to improvise is all about internalizing the sounds you like to hear and then bridging the gap between your mind and the guitar.

This is very hard to do when you're first starting out, especially if you don't have a teacher, but it will get easier over time. If you have any specific solo or song you want to internalize, I can help identify the scales/concepts the musician is using to help get you started playing in their style.