Depends upon the destinations and how many days you are spending. I suggest selecting a tour packages will be more safe and comfortable for you. There are more tour operators in Kerala providing Kerala group tour packages for travelers. You can check one of them here. https://gokeralatrip.com/kerala_group_tour
I will say depends on the places to stay. Most people prefer to stay in hotels and good resorts. So if you want something offbeat can check my profile.
Https://tripoto.page.link/gnwpbKSge9tQjt7p6
Can check out this. You can travel in KSRTC buses and book them online. There are zostels and places at hostel.com available. You can spend 16k per day and 1000 per day for a room.