Regular machine needles (11-14 size) will work for general sewing. Buy a reputable brand (I like Schmetz or Organ or Superior) and avoid the $ store cheapies. Change your needle after each project or about 10 hours of sewing time even if you haven't broken it. More tension problems are caused by needles with burrs or nicked off points than by incorrect tension settings. If you want to do other types of stitching you can buy quilting needles, top stitch needles or titanium needles for longer wear. There are lots of options out there.