Start small. If you try to do everything at once, it will feel overwhelming and you'll inevitably fail to meet the expectations you've set for yourself, which may only push you away and further from your goals.
I started with a simple dream diary. Dreams are probably the most magical thing the average person interacts with almost every single night, whether they want to call it magic or not. Develop this habit before attempting more advanced or complicated. It builds a new routine into your daily life that's magically oriented, even if only slightly, which can then act like a stepping stone towards other magically oriented goals, like reading a particular book in full, creating an altar space, performing a ritual, etc.
Also keep in mind, discipline is basically just another word for willpower. Willpower is a finite resource, once you spend it on resisting the impulse to do one thing or not do something, you have less to spend later on potentially more important choices. The trick then, is to completely remove those things in your life that test your willpower, rather than trying to overcome the temptation of them with sheer resolve. By not even having the option to spend it on meaningless distractions, you have plenty left to tackle the truly important goals.
Examples: if you have a penchant for raiding your pantry and eating all of your snacks instead making a proper meal for dinner, stop buying snacks completely and substitute for healthier more complete meals. If you struggle with doom scrolling for hours, delete all the apps on your phone responsible for the behavior (social media and tik tok are a plague on our attention span for this reason). If you can't help watching lots of porn and straight jorking it all night, consider downloading browser extensions that specifically aim to block such websites and images. Anything technology related like that can also be rectified in part by downgrading to less sophisticated technology, like trading in your smart phone for ye olde flip phone.
In short, discipline in all things, mundane or magical, requires taking small steps and taking proactive approaches.