Need help installing propane lines on my skoolie (Linden)

Hello I'm currently finishing up my school bus conversion and in desperate need of help installing the lines from my propane tank mounted on my bus to my 3 propane appliances.
(Furnace, stove, water heater) I've watched countless hours of YouTube videos and taken countless notes trying to figure out the proper way to do it and now I'm concerned that I won't do it properly and would love some help from someone who has knowledge connecting everything properly.
To my understanding I am to use 3/8inch copper pipe using flare fittings to attach everything.
I want to run the lines under the bus and drill holes through the floor to connect the line to the appliances.
Desperately need this job done ASAP as I need the furnace to stay warm as I am already inhabiting the bus.
Thanks for reading this and please reach out if you think you could help.
I'll pay whatever you believe is fair.
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