I can play a few chords in my guitar, which is tuned, but the sound is dull. I am also struggling to properly reach some of the strings when playing.
When you say dulled strings, it is often due to using old strings. The sound coming from the strings will sound dull whether you play them open (without pressing on the strings) or not. In your case, it sounds like you are confusing dull strings to muted strings. Muted strings will only sound dull once you press them with poorly positioned hands and is a sign that you lack proper technique.Beginners usually experience muted strings when they try to play a chord. It is caused by:
1. Fingers brushing with or against nearby strings
2. Pressing the strings too close to the fret
3. Not pressing the strings hard enough
Identify whether your strings really sound “dull” or if they sound “muted, instead. Form a chord and pluck each string one by one so you can find the string that does not sound right. From there, adjust your grip and your hold on each of the strings. Try to identify what causes the dull sound with the reference above.
Try adjusting the angle of your grip to more of a 90-degree angle if you feel like your fingers are brushing against the adjacent strings. You may need to adjust or rotate your wrist angles more under the guitar to get it right.
Having a live instructor or an experienced guitar player can help you point out or identify what you are doing wrong.