Need help with a 4 days itinerary in Kerala

Dear friends, I will be traveling to Kerala in March and will be there between March 12-16. I will fly out from Kochi in the morning to go back to Europe and was thinking about flying in Thiruvananthapuram and start from there. I would really like to go to Munnar and see the tea plantations and the view from the highest peak and then see the backwaters. I would also like to do an Ayurvedic massage and yoga if possible. What do you recommend for the itinerary? Also, what would be the best way to move around (I’m traveling solo so maybe something safe and not so expensive). Thanks a lot 🙏🏻