SOLDIERX.COM Nobody Can Stop Information Insemination

I'm new to the forum going by the name S0j@(soja) I just finished doing my final diploma exams.scared and stressed asf!
I'm looking for a guide on how to write hardcoded backdoors on systems coded with basically any language but I prefer mostly c/c++ or python(not limited to anything though).
I just want to secure some of my systems since they are some very shitty buyers outhere.it's a jungle and all must be prepared.
Kindly assist if you see this I will appreciate the help.
i'd also appreciate a guide on how to write mining scripts or anything touching on that area.
Much Love!