#1
so me and my friend were jamming today, and we were playing in A so we were taking turns playing lead over a basic chord progression, i cant remember what it was.
when i was playing i was really just winging it, just playing random notes of the scale, and at some points i thought that it really didnt sound very good. i dont know most of the notes im playing, im trying to slowly transition that in. but even if i did, i wouldnt know what notes sound good with one another. so i guess what im asking for is some advice based on what i wrote
#2
As far as "sounding good" and making melodies, focus first on the pentatonic because those five notes all "sound good" in that there really aren't any dissonances (rough sounds) in the scale.

If you play a G# against an A (both notes are in A of course), it will sound very bad! Of course Jazz players often use this to build tension, but you'll learn about that later.

To me scales are less important/valuable than arpeggios, and in theory, arpeggios are just scales that have fewer notes in them.

Fortunately, playing in pentatonic gives you most of the notes of the major chords of the scale anyway, so a lot of "licks" are arpeggios!

Another thing to try, though, is a pent (the blues scale) off the 5th fret. This is the "dominant" sound, which is a major sound, but a weird one. It's been used forever, but most recognizable as Blues.

Try the exact same scale on the 2nd fret, F#, and you're in F# min pent, which is a harmonic pentatonic scale in the key.

Try messing around with

0
0
0
0---2
02/4
0

That sort of idea sounds great over A Major.

Over DMajor, try the same one string higher.

That should give you some more ideas to mess with. Good luck!
"Virtually no one who is taught Relativity continues to read the Bible."

#3
Well, you didn't give us much to go on, other than you were jamming in A. With that, let me say that ear training, scale training and being able to improvise are really key. Try downloading some practice tracks, or jam tracks, and work on those. Part of my evening practice routine is to use jam tracks for about an hour. Don't hold back. Nothing is a mistake. You'll play some things that sound cool and you'll play some things that sound like crap. Do this for awhile and I guarantee you'll improve.
#4
thanks so much Bubonic Chronic (great username), you also answered my other question on why the pentatonic scale would be used instead of the major scale