How to eat healthy food?

I wanna start eating healthy cause everyday I drink alot of sodas, pizza and Mcdonnals.I 22 and I live with my parents still My mom make white rices with beef or chinken and salet with tomatoes.I'm also trying to reduce panics I did panic on sunday and it wasn't good.And I believe that evers since I drink alot of soda in my early ages I was doing harm to myself accumulating cholesterol or high blood pressure I'm not at home not I'm far away and I,m on the library so what I saw around here is mcdonnals,pizza,dunkin donuts,and a chinese store I do got alergy to sea food so I could pick is vegetables with salet and beef for $5 but their drinks is sodas and diet soda but I still tihnk is not healthy ust because is diet is still do harm in my opinion.They probably go juice but I,m not sure what they got I found. a 7 eleven and they got tuna fish sandwitch and tropical orange juice that cost two dollars but all I got is 10$ and I,m hungry but I don't know where to sit down not at the street? lol um can anyone tell how to eat heathy.I don't wanna limite myself just going to mcdonnals I could buy a two double cheese burger for 3$ but that's limited myself.