The 'SDK' for Microchip microcontrollers is named MPLAB X,
It is a IDE for development , program build, programming and debugging environment for microcontrollers.
In addition to MPLAB X, you will need the Compiler package for the family of microcontrollers you are going to use.
There are 3 compiler installation packages: XC8, XC16 and XC32 for 8-bit, 16 bit and 32-bit PIC microcontrollers respectively.
Since Microchip bought and merged Atmel some years ago, also those microcontrollers are suppoorted by MPLAB X.
The compiler installation packages contain both C compiler and assembler for the devices it support.
In addition to the compiler, the installation package also contain device specific files
with symbolic names for all registers and control bits in every PIC microcontroller ever produced.
Within MPLAB X development environment, there is also also Simulator that make it possible to perform development and debugging excercises without actual microcontroller hardware.
Even if you have a ultimate goal, you may as well forget about that while learning about how the development tools and microcontroller fundamental operations work.
Better perform much simpler exercises until you are familiar.
There are tutorial examples in the website linked to by katela in message #2
Also there are tutorials and instruction materials in https://microchipdeveloper.com/
You will probably not be able to figure out how TV remote control work by DMM only.
They work by fast coded signal sequences, so you will need DSO oscilloscope or Logic Analyzer
to investigate and verify the stuff you eventually make.
Do Not expect to be able to read or study the programming of a commercial remote control handset.
Even if it is built around a microcontroller, any developer with a minimum of buisiness sense,
will take steps to prevent copying the program memory, to discourage pirating.
If you do not even know what make and model of microcontroller is used, then you would not know what tools to use either.