The episode takes place roughly 40 years before A New Hope.
Most of the characters get a brief physical description, highlighting the elements that matter to me and leaving the rest a little open to interpretation/imagination. But, if it helps, I'd say Obi Wan is in his early thirties and Anakin is 15 or 16 with Leia's coloring (brown hair and eyes). I'd put Manx in her mid-twenties, Rohn and Bail Organa in their early forties, and Palpatine in his seventies.