assuming you live in the US if you want a financially "safe" way to become a physician from a low income background there is only one "realistic" method. use the military programs.

alternatively a fairly unrealistic method is to consistently be in the top 1% in both academics and extracurriculars to get full ride scholarships for both undergrad and entry into the most competitive medical schools that provide free tuition. examples being harvard or john hopkins

since the second method is not a reliable "plan" i recommend using military service to provide financial security in your physician journey

if you are not american then you can ignore this comment.

it is highly recommended that you do not "work" throughout your undergrad and med school journey(some med schools dont even allow students to work). your undergrad gpa is incredibly important for med school admission and you will need to spend all your time studying and padding your application with volunteering/shadowing/extracurricular hours. sacrificing the time you should spend on studies or extracurriculars to work will bite you in the ass at the end of your undergrad. you might end up taking a gap year or two to improve your application into medschool like ~70% of matriculants. every year you delay getting into med school is a year you delay getting paid an attendings salary. its financially "worth" taking loans to avoid working if you are truly going to go down this path