@Brandon ***********
this is a really important way to start that you mention , the initial 60 day tourist visa is the best way to begin, it saves money and time, also depending on ones home country, and the immigration office you apply at, you can get a letter of income validation from your embassy/ consulate for the Thai immigration department, it speeds the whole process up. Well, not really speed it up but it cuts out a couple of steps.
It seems daunting but you don’t need an agent, it’s illegal and could backfire in the future.
I just got my 90 day extension stamp in this process so next trip in may is 1 yr retirement stamp.
It’s not difficult to do on your own but you should have a Thai translator with you at the offices