Feedback happens when a sound goes through a "loop" at high volumes, that is, the noise from your guitar is amplified through your amp, and the amplified guitar noise is picked up by your guitar pickups, which, in turn, send it right back to the amp, over and over and over. That leads to that sometimes beautiful, mostly annoying and deafening sound we call feedback.
It may be that you're turning your amp too loud, rather than not loud enough; or maybe you're standing too close/right in front of your amp. Try wither turning the amp down a notch, or moving the amp further away from the guitar.
You're guitar probably doesn't need refretting, unless your dad's boss wear sandpaper gloves to play guitar. Instead, it's most likely a combination of your friend's guitar having lighter gauge strings and the fact that your fingers need to develop some strength and calluses to play perfectly clean.
see you on the dark side of the moon