I had to doublecheck that this is not a thread from months ago.
Did I have a time skip
What hotel reservation? Quarantine? Covid test?
If you are fully vaccinated, all you need for the Thai pass application is the Covid insurance (10000 USD coverage) and your vax certificate uploaded.
No tests pre departure, no test after arrival, no hotel reservation.
You arrive, your documents and QR are checked and you are free to go where you want.
Your decision to relax in Bangkok or continue north.