@benlam11 I too wanted to lose weight before my liver transplant. I actually already was, and I used myfitnesspal.com to help me. You have to be honest with it, if you are not you are only cheating yourself. You put in everything you eat and drink each day. Sometimes it's surprising when you see the nutrients in various foods. You can tell it your current weight and your goal and when you are done recording everything for the day it tells you "if you do every day like this you will weight XXX in five weeks. So it is encouraging. If you don't eat enough it won't give you the end of day numbers!
I lost a total of about 90 pounds overall, some before any of this, and I have in the last year gained back 10 so I am back to using myfitnesspal to try to drop those 10 pounds.
I did also use a fitness tracker to keep motivated with exercise, and I have a great scale, it tells you how much of your weight is fluid! I realize it is not medically accurate, but it is a good gauge. If my weight goes up but I see I am retaining fluid, I don't feel as bad and I know I have to be even more diligent about not ingesting sodium.
Good luck with the weight loss, and also with your future plans. I understand the wait for a kidney transplant is even longer than it was for a liver transplant. I don't think that getting a transplant depends on when you got listed, it depends on your condition.
JK

It's different for each person, but as a general rule, limit sugar and junk carbs. After that there are many factors involved, that have to be sorted out, blood work and hormone levels etc.