A protagonist that discovers cultivation by himself. They don't have seniors that can guide them or a sect to join. An mc that cultivates in a non-cultivation world or the mc being the first one to start cultivating is also fine. Something like spiritual attainment of minghe (mc is one of the first organisms in the world) School topper is reborn (mc transmigrates home from cultivation world and cultivates on earth)
Strictly speaking, Tales of Herding Gods has MC and his allies creating their own cultivation method after 500s. Spoiler: Also Even the final stages of conventional cultivation system in that world was popularized by MC when he travelled back in time.
Body Cultivation Ancestor on lnmtl (Why specify? Because lnmtl has remtling every time enough badly mtled shit is spotted and corrected by readers who either know Chinese or can clearly tell what is supposed to actually be in place of wrong words by context. It got remtled 16 times so far and current suggestion box is at 40/191 suggestion words which means a very decent reading exp for mtl ). Anyways, onto the novel itself. There absolutely is cultivation and sects around, just not ones MC can follow. The entire novel is him building a path forward from mortal martial artist (the linear fighters helpless even in front of mere Qi Refiners(1st realm)) to Qi Refining- Foundation Establishing- Core - Nascent Soul- ???(haven't read farther than NS myself but its there- I left it off in early 600s). Its really cool how author is looking over all kinds of known neat tricks that laid together can allow a cultivator to form a new path. Its on chapter 1343 so far and MC built a sect of his own because building an entire new path of cultivation isn't just something for him, he needs more people to research and broaden the narrow path he discovered, there is also the small sidegoal of avenging the sect he worked in(he needed their treasure refining knowledge for his path and came to like people there, there was a very successful raid on them and remnants joined him as starters of his sect). It also takes time. Yes, this is a strong path, but its totally new and a lot of time is spent either on thinking what needs to be done to cultivate further as a body refiner, testing if it is viable as a formal progression step, what are the strengths and weaknesses (and how to rectify flaws) and confirming which means of going further in that path is a deadend/failure (happened to MC once that I saw. Needed to destory his own a Foundation and go back to Qi Refining and think of another way or be stuck forever at FE realm). So all in all, if cultivation pioneering is what you want, this is it.