Many people train by walking and carrying their packs, but I think that maybe some sleep training may be in order.
First, buy a wobbly bunk bed and the most uncomfortable mattress that you can find. If it's winter make sure to leave a window open in your room. If it's summer close all the windows - and no cheating by turning on the air conditioning. Leave the door to your room open and set up a light on a timer in the hall to go off at random times to simulate pilgrims getting up in the middle of the night to use the bathroom. You are going to need a lot of lights and timers for this training.
Set a couple of alarms to go off at least an hour before you want to get up. Make a recording of people rustling plastic bags and whispering loudly, and set that to play two hours before sunrise. Perhaps hire someone to come in and shine a flashlight at you at 4am. Set your overhead light to turn on no later than 5:30. And don't forget to play a recording of people snoring and rolling over in squeaky beds on a continuous loop. Sleep under these conditions for a month. Now you are ready for the Camino!
I'm thinking that if you have an Alexa device you can program a pretty good albergue simulator.