Learning all 5 positions of the minor pentatonic scale is not required to learn how to solo. Using just a few notes from the scale is more than enough. In the beginning, you should concentrate on just using a few notes, for example the 1st scale shape, or the top 5 notes of the 2nd position minor pentatonic.
Learning how to connect the scale patterns might also be useful, but not required at first:
Now learning to solo is not just a matter of knowing the shapes and notes. Timing is very very important, as are the vibratos, slides and bends. That adds the style.
The best way to practice is by playing along to backing tracks. Let's stick with the example above, a G minor 12 bar blues progression.
In the key of G, the I chord will be the G, the IV is C and the V is D.
Those notes are present in the pentatonic scale as well, and you'll notice that just by playing that given chord root note during the backing track, it'll already sound really good. From there on, you can add notes in between, the chord root notes, which will build your solo.
Here are a few tips on how to build your soloing technique:
- Add the vibrato to basically any note you hold out
- Instead of just plucking a note, slide up to it
- Do slow bends up to the next not in the scale (on notes that are or 2 semitones apart)
- Slur the flat 3rd (2nd note from the root in the minor pentatonic)
- Repetition of riffs is a good thing. Most beginners are tempted to just pluck all over the scale, but creating a nicely timed 4-5 note riff, and repeating it, will get a really nice effect.
- Listen to blues guitarists and listening specifically for the techniques they use while playing.
Hope this helps, let me know how you progress!