Hi there!
Well, if you are using desktop. 1GB RAM or more in a HTPC media player appliance-like computer dedicated for Kodi, and 2GB or more in a computer for multipurpose use.
Drive space
Minimum: 4 to 8GB
Recommended: 16GB or more
Depending on how big your video library is. Most of the space required for Kodi comes from the images/artwork cache, which can be adjusted.