Does anyone know how to use a thermal printer?

Ummm, I don't think that would be a good idea really. The coding that those printers use is very specific and unique to each manufacturer, and any regular print from a regular word processing program would not be compatible. They are also not designed for really long and wide prints like you may be trying to do. You could manually create the code to send data to the printer, but it's usually easiest if you buy a software program specifically designed for use with thermal printers. The software is mainly geared toward label format printing and not regular text printing, though it can be done.

Most thermal printers limit their output to a fairly narrow print media, usually labels, of about 4" or less, though there are some thermal printers that are designed for wider media of about 6" or so. Also, printers of that size are usually several thousand dollars. The printheads on those printers can, and do, wear out and can be easily damaged if you're not careful. Most printheads for the 4" size media printers usually cost around $400-500 dollars to replace (part only).

I don't think thermal printers are the best use for printing reports or anything like that on regular paper. You will need thermal compatible media to use, that is either thermally sensitive, or you will also need thermal ribbons for printing on non-thermally sensitive media. Any of those will also run at a higher price for the supplies than you could probably print with a regular laser or inkjet printer.

Stick with a good laser printer would be your best choice.