Can I extend my Tourist Visa in Thailand and is there an easy way to do it?

If you’re coming in on a visa exempt entry you can extend that once. You would go to Muang Thong Thani office to extend. If you’re coming in on an actual tourist visa, you’d get 60 days on arrival, which can also be extended, but you would go to the Chang Wattana office for that.

You need a flight out within your arrival limit days else you risk being denied boarding by your airline. Some have got away with it but it’s a lottery whether you will.