The 40 day guide provides the best framework for advancing. After, you can substitute different exercises, but the basis of this should be the same: https://satanslibrary.org/hp_hooded_cobra_40_day_meditation_program.pdf
Also read the Witchcraft and Meditations Pages:
https://www.satanisgod.org/www.angelfire.com/empire/serpentis666/Satanic_Magick.html
https://www.satanisgod.org/www.angelfire.com/empire/serpentis666/Satanic_Meditation.html