I would like a light up garland around my banister going up my stairs

Try your local DIY store or Xmas shop

Measure the length of the bannister to determine how much garland you will need and length of the string of light you will need. Now if you are going to wrap around the bannister be sure to add extra length. You can do this two ways. 1. wrap the lights around the bannister and then wrap the garland around the bannister over the lights. Or 2. You can twist the light and garland together first before wrapping around the bannister. Make sure the end of the lights is closest to the electrical outlet.

Use battery operated lights. They're the boom!