Re: Having Problems when I try to improv solo
The absolute most important thing any guitarist that wants to get into music theory can do is learn the note names for the whole fretboard. It may sound like a huge chore, but if you're methodical about it and devote maybe half an hour a day to it, you'll be getting pretty competent within a couple of weeks. After all, it's just the same 12 notes repeating.
Once you're familiar with that, the next logical step is to learn the seven positions of the major scale. If you eventually want to move on to modes, you'll be glad you did this first. While you are familiarising yourself with the fingering patterns, be mindful of the intervals between each note, the note names and how many steps in the scale each note is from the root.
This all sounds boring because well... it is boring. But it is pretty much the basic building blocks behind all music and will open up enormous potential for improvisation. The key here is to set aside some time after each session to stick on a backing track and just play and have fun. Incorporate a little of what you've been learning into your playing each time and it will really help you digest and make practical use of all the theoretical stuff. Seeing your own progress will also help to keep you motivated.