I've been playing for a month now, and I've been trying to practice just change for weeks now, but it's not really working.
I'm using this fingering for A chord
x02130
the problem is that the G string keeps buzzing because it's too far behind, and if I try to push it harder, my fingertip starts to hurt a lot
try x01230 or x02340 so the fingers tips are closer. try just the buzzing finger until it doesnt buzz. How close to the fret do you need to go?
Until the fingertips are hard a little pain is normal. Are your nails too long on the fretboard hand? make sure they are very short.
Or just live with it buzzing a bit. Thats also pretty normal early on. Give it time :)
Dm is best played using x00231 (yes, open A is o.k.) then finger A with 002220 - but - try using middle finger on strings 4 and 3, with ring on 2nd string 2nd fret. the concept may seem odd, but it may just work for you - it does for me.
You also need to try out different fingerings for the A chord - bear in mind that because pinky is smaller than index, middle+ring+pinky take up less room, so you could fit onto that 2nd fret more easily. Don't always take tutor/youtube fingerings as gospel - experiment with your own. You may find two different ones for the same chord shape, and use one or the other depending where the last/next chord was/will be.
First let's make sure your instrument is in good working condition. Instruments of poor quality and/or poor repair will be harder to play.
Does that note always buzz even when you're playing it in isolation? If so, then your guitar might have a dead fret. You should take it to a technician.
If it will ring without buzzing but requires excessive force to do so, then this might indicate that your action is too high. A setup will fix this. It could also mean that your strings are simply too heavy for you. Try putting on lower gauge strings. Note that changing string gauge will affect your action and intonation. Drastic changes in string gauge might require a setup.
If the above troubleshooting hasn't found any problems, let's address your technique.
The buzzing is probably because your finger is too far from the fret. x02130 is a good fingering. Focus on getting fingers 2 and 3 right right behind the 2nd fret so there is more room for finger 1 behind them. Generally speaking, you should always place your finger as close to the fret as possible without being on top of it. If your finger is too far back from the fret, it might buzz.
It might be that you're not pushing hard enough, and pushing a little harder is the solution, even if it hurts. (Within reason, see above.) It is completely normal to have lots of pain in the fingertips while you're first learning to play. It's unavoidable. Don't worry though. Your fingertips will soon form callouses and then you'll feel nothing.
Your question mentions changing from Dm to A. I doubt the problem is with Dm specifically. Does the buzzing only happen when you change to A after playing a different chord? Then this is simply a practice thing. Practice chord changes slowly and make sure each finger is landing in the appropriate spot and not touching anything it isn't supposed to be touching. Repetition, repetition, repetition. Always practice in time with the music, even if you need to go at a snail's pace.
The fingering (x, x, 0, 2, 3, 1) to (x, 0, 1, 2, 3, 0) for D- to A makes the most sense to me since you have the least amount of movement, the 2 finger stays where it is and the 3 finger slides back a fret. The index has to jump a few strings but the hand is well anchored. The fingering you have provided is also a very good option for moving from E7 to A, (x, x, 2, 1, 3, 0) to (x, 0, 2, 1, 3, 0). It would seem like these are the same chord but the 2 is fixed while the 1 slides up a fret and the 3 down a fret when going from E7 to A. There are multiple fingerings of the same chord and the "best" choice is driven by the chords before and after.
As for the buzzing and or pain, it is true that if you are not fretting the note close to the fret you can get buzzing and for this reason the fingering (x, 0, 2, 1, 3, 0) would buzz on the G string since the 1 finger is further back. On a classical this is easier to fret since the strings are typically farther apart. The fingering (x, 0, 1, 2, 3, 0) may cause buzzing on the D string for the same reason. If the issue is movement try the fingering I provided. Even though the index may fall farther back I think you will be able to control it better since there is less movement. If all else fails I'd say look into having your guitar adjusted. Do you know if the action is too high? Or if the nut or grooves in the nut are set too high? If so this can cause the guitar to be difficult yo play in the open position. And pressing hard enough to get the strings down can cause the pitch to bend out of tune. Of course setting it too low may cause buzzing for other reasons. If you are not familiar with adjusting guitars and suspect that yours may benefit from a professional adjustment look for a store that offers basic set up services and ask the tech if the action is high. Tell them your issue and see if that is an option. They may say you just need more practice with those chords.
The point is that you have to hold your wrist different when you play dm and A:
Dm: the wrist is parallel to the strings similar to the C-chord (finger 2 fret 1, finger 3 fret 2, finger 4 fret 3.
A: you should turn the wrist 90 degrees and hold it parallel to the frets as all fingers have to play in fret 2.
Optional you can push the d-, g- and b- strings all by the same finger (middle or ring finger unblocking the e-string by lifting this pseudo barre finger 2 mm.
The best solution is you practice all alternatives: 234, 345, and the 2 others mentioned above.
