Going in ,on a us passport, do you have to have an exit date / exit ticket to enter ?

Do I need a return ticket/exit ticket with a 60 days tourist visa? Thank you

I hope you are all having a wonderful day. I have some questions, l need help with please.

We are landing in Chiang Mai on the 1st June, We are currently in Cape Town and live in London but travelling in our 2 kids who are 4 & 6.

My question is do we need an exit ticket and we land in Thailand? We would like to stay in Chiang Mai for 3 months, our ticket was from London to Cape Town to Chiang Mai. We don't really know where we want to travel to next, hence we haven't bought an onward ticket.

Next question is how do we extend our tourist visas from 1month to 3months?

and finally we haven't book our accommodation yet, we tried to book with perfect home last week but they said to try and book 2 weeks before we arrive. Apart from Airbnb can anyone recommend any websites to rent an apartment. We are looking for a 2bed.

You help in much appreciated.