SOS Encounter: Route 11 (Only in Sun & Moon), Brooklet Hill, Lush Jungle
Walk: Lush Jungle (30%), Brooklet Hill (20%), Route 11 (10%, Only in Sun & Moon)
Its base catch rate is 190 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Repeat Ball, Sport Ball or Poké Ball.
Evolution: Paras → Parasect (Level 24).
Paras in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)