ok so school really confused me with how and what i should eat, and heathy living . . . I have been told that i could develop a problem if i dont change my diet. . no clue if this is the right reddit for this but im hoping

im 24 male(MtF) 125lb 5'7"
i have been working on changing up my diet and currently my diet is ether a premade Teriyaki or Yakisoba for lunch and ether home made meal or Progresso chicken soup for dinner(depending on if im working)
my snacks are pretzels, corn chips, nuts(variety), (white)cheez-its, and pop corn.

my biggest problem with foods is i do not have a fridge and 99% lost as to what i should and should not be eating. . i have cut out as much sugars as possible as its in most things these days. . and so my biggest problem is sodium. .
having yogurt, fruits and other stuff like that is hard as i dont have an easy way to store it and its extremely expensive. .

i want to start eating heather but have no idea if or what im doing wrong and what i can do better?
this is compounded by the fact i wont eat most foods as im autistic and absolutely repulsed by stuff like dried fruits. .

can someone please give me advice?? also if this is not the right sub or if there is a better sub please tell me?