To reach Kasainath, you will need to ride/drive all the way to Dodamarg by crossing the Goa border.
Time & Distance from Panaji: 1 h 17 min (40.8 km) via SH 2
Time & Distance from Mapusa: 49 min (26.5 km) via Mapusa – Bicholim Rd and SH 2
Time & Distance from Margao: 1 h 54 min (66.9 km) via Hathkhamba-Goa Rd
From the Dodamarg main junction, you will have to go a little ahead and take a right that directs to a little village until you approach a temple (P.S. This is not the Kasainath temple). You will need to park your vehicle here and then start walking for the trek.