Have you used these modules before?
Well you can use a library function to set up the UART or ADC, which personally I do not recommend because if you don't understand everything it's doing to the letter then there's a significant chance you're not going to be using it right. If you DO know exactly what you want to do, then just assign the reg directly. That's what most people do.
I have always just looked up the module functionality and assigning them in C is straightforward:
ADCON=0b11110000;
You will probably need to write an interrupt handler, that's in a format specific to a particular C compiler. The syntax is different for PICC18 and MCC18.