For the basics of the Chinese diesel heater controllers this guy is easy to follow. Here is just a sample. Youtube is your friend with these heaters because there is no support or understandable instructions. Another good resource of info is the Chinese Diesel Heater Facebook Group. I would suggest lurking and reading the FB group for a while because they consistently roast noobs asking redundant questions. But there is a wealth of info there.
Not trying to rain on your parade but I have two of these in the workshop to toy around with and have an Espar D4 in the SMB for the last 11 years. The Chinese heaters work well but I'm not sure I'd put one in the van vs the Esbar. Just my opinion.