mshutchis,
The needle is the most important part of the machine. The wrong needle, the wrong type of needle, a bent, chipped, dull, or rusted needle, or a poor quality needle will make the machine malfunction.
Don't give the one in there to much thought, just put a brand new needle in it and go from there.
The 301 takes the standard 15x1 needle. The Singer number is 2020.
Not all Singer needles are bad, but their quality control varies from great to grotesque so it's best to use a Schmetz or Organ brand needle due to their far better QC.
While your changing the needle pull the bobbin cover and needle plate off and clean the bobbin area to make sure there's nothing in there interfering with the stitch making process.
Joe