Ok just from a quick google search here’s a couple things.
The pic18f452 micro-controller is in now almost obsolete, soon you will not even be able to purchase it and if you do need another one you will have to pay more for it.
PIC18F4520 is the microcontroller which is the replacement for all new designs, I would highly recommend you switch to that one, it’s about $2 to $4 USD so it’s relatively a cheap chip.
Also here are additional benefits to switching to the micro controller to the one I’m suggesting:
Better support, it’s not an old obsolete chip, the replacement is currently in production and there is more community support and learning literature behind it.
Here is one learning resource I found right away:
PIC Assembly Language for the Complete Beginner