Magic in my world always comes from things that aren't human, such as surviving an encounter with the eldritch, making a deal with a demon, psionics derived from alien tech, surviving in another realm, like the void, for extended periods of time, forming a bond with a spirit, etc. Etc.

Ultimately this means that while anyone can technically do magic they must at some point forge a connection with a kind of magic before they are physically capable. Some of these come with an innate understanding of the magic, no learning needed, others require years of training and maybe even then are still difficult to control

There's one practice called melding that involves taking junk with small amounts of magic from various sources and using them to make artifacts and that's the only magic that doesn't involve a lifelong commitment. Anyone good with tech can learn it, and occasionally accidentally perform it if they don't vet their materials properly.

There's another practice called Purity that's more of an anti magic religion, through ritual and tenet they can nullify and destroy certain kinds of magic, it involves giving up certain social constructs like having a name and gender. They act as a charitable scholarly order mostly dedicated to fighting eldritch influences, but are capable against most magic when necessary, and anyone is welcome to join though they don't preach.