For that, it's eaiser and cheaper to just buy a cheap controller--$20-$30 USD would get you one (possibly even less).
If you want to design one and build it yourself, and have the time and money to do so (as it will cost a LOT more than buying one pre-made), you can look at the brushless motor controller chips from various companies like ST Micro, TI, Infineon, etc., all of which have development kits and application notes that will help you with the process.
There are also various Arduino and other microcontroller (MCU) based projects around the internet that have code examples you can use to build a controller from, if you know how to code or can follow their directions to build what they designed (if it works as-is for you).
Or if you are willing to look for them in the Motor Technology section, and read them, there are a number of controller design threads here on ES that go thru the whole design process as they create their own controllers. These are generally going to be more complex than you are after, but you could leave out the features you don't want. The simplest is an old thread by Jeremy Harris using a Motorola chip that is probably not made anymore, but if you can find one of the chips you can build that simple BLDC controller.
