**NO CLASSES IN NEXT FEW WEEKS**
Playing - fingers, plectrum
The hand that presses - frets - the strings needs to have short nails. For most people, this is the right hand.
For the other hand, there is a choice:
You can use a plectrum - a tiny bit of plastic. Also called a pick. This is good for strumming, and for single notes.
you can play with your fingers. Your thumb might play on strings 4, 5, 6, and fingers 1, 2, 3 play the higher strings. Slightly longer nails make a louder sound, but short nails are OK.
It also depends on what type of music you will play. It is a good idea to learn both ways.