Hii Tom,
Both SP and SD can be purchased at Steam as a one-time payment, with updates till the end of 2024. You can of course keep on using it after that.
Substance Painter and Designer don’t magically turn you into a good texturing artist, though; you’ll have to put in the effort. (There are many ‘amateurs’ in the Substance kitchens, whose food I wouldn’t like to eat.)
