I mean i want to improvise, but i have no idea where to start learning- i know 3 scales in one key, but nothing beyond that. So where to begin???
Try backtracks, it helped me although I still have the same problem has you do.
Download the backtracks of your favourite solos and try to improvise. I heard it comes from practice...
Improv, a lot. Start with basics like the major scale and triads up and down the neck, then apply that to arpeggiating the chords of your rhythm all over the neck. A solid foundation of that will help a lot more then learning as many cool licks as you can. Beyond that, just improv a lot and work on developing your ear. Make some drum tracks and play over them.
Learn chord construction. I'm sure there are plenty of UG lessons that cover it, as well as thousands of other sites. When you first start improvising, you need to learn to play chord tones over your harmony. This will give you a framework to build more interesting stuff from.

Do not, I repeat, DO NOT just start playing random notes from a scale over a progression in the same key.
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Play and Listen.

Mostly Play.

Nope, mostly listen in the early stages.

The biggest mistake people make when trying to improvise is playing through a couple of scale shapes they've memorised and hoping that somehow something good will come out of it. However that rarely, if ever, happens.

You have to have an idea as to what you want to create when it comes to improvising. You don't necessarily need to be able to compose a symphony in your head but you need something, at least a general sound or feeling that you're aiming for in your head. The backing may well suggest something to you, then it's up to you to flesh that out and create something.

If you don't get what you wanted then it's no big deal, you just try something else. The more you do it, the better you'll get - but the crucial thing is to listen to your backing, listen to how the notes you're using interact with it and listen to what you're playing and be prepared to change it if you don't like what you've made.
Actually called Mark!

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