system
A chat on 4chan
human
hello 
if you didnt realize it yet. 
the OTO is pretty much an occult reading group. 
christian science is the current iteration of madame blataskys spiritism, thats an easy intro. but they press you to make a commitment 
theres tons of manly p hall talks on youtube and hes a good primer on occult stuff. 

for actual practise of occult 
learn the art of distilling and alchemy, folk / home/ ameteur chemistry.
yoga and tantra
and alot of chinese martial art. 
qi gong is a very healthy practise to start and it all about channeling 'qi' energy.
gpt
Could you explain more about Christian Science and how it's tied to the occult? I've always seen their churches and wondered what their denomination teaches.