And if you stay in Thailand for less than 90 days, you can pay the fine when you leave the country. But it will affect the next visa application. If you stay more than 90 days, you will not be able to enter Thailand for 3 years or up to 5 years depending on the case.
If you have traveled outside Thailand You don't need to travel to Laos to re-enter Thailand. You can apply for a Thai visa from your country of origin immediately. but if you come to Thailand visa due and want to stay That's why you choose to travel to Laos. to apply for a visa to enter Thailand again