In any musical group someone has to play the tunes. Even with a singer fronting the band, the bass player, drummer and rhythm guitarist aren't enough to carry the music: a soloist is necessary to give the sound some variety and interest for the audience.
One area of guitar playing the aspiring lead guitarist must master is use of the plectrum. Playing scale, riffs or melodies, try different combinations of up and down strokes or playing all upstrokes or all downstrokes. As with all aspects of learning to play a guitar - remember to have fun with it!
Maybe this is a good place to remind you to get a sound recording device of some kind, no matter how primitive. Use your recorder to hear what you really sound like. You will hear fluffed notes and little moments of hesitation you don't notice as you are playing. Also you need to double check your ability to keep good time. A metronome is necessary, but the cassette recorder lets you really hear your playing.
The question of how fast to play should also be touched upon. Speed shouldn't be tried for by rushing. If you choose to use special exercises designed for cultivating speed, the physical ability to play fast is aquired in time, depending on how long you practice every day and how hard you work on relaxation during practice.
Your guitar solos are mashups of other people's riffs you have learned, your efforts with pentatonic scales, and your experiments with making up music on the spot. The process of learning to play improvised solos begins with using riffs and breaks you know you can use, and as you get some experience playing in public your guitar playing will become more spontaneous. Sometimes you'll even surprise yourself with what you can do!
The time you spend playing should not always be with musicians at the same stage of playing as yourself. There's nothing wrong with feeling lost and floundering around. But a band should really be made up of guys with varying degrees of talent and ability so that there's a process in motion of musicians helping and being helped by each other.
If you feel that you need help with learning how to play guitar solos Lead Guitar Secrets is the only worthwhile course designed for lead guitar. They have free sample video lessons so you can check out the course before you buy.