How do I start the process of retiring in Thailand, and should I use a service or handle it myself?

Thanks for accepting me to the group firstly.

I want to retire in Thailand this year. I have the income I’m over 50.

Where do I start. Is just easier to pay a company and let them sort it out or do it your self.

Ps. I’m not the greatest when dealing with paperwork and forms.

Thanks in advance.

Steve.