I could go into excruciating detail about nutrition, but a good rule of thumb is to avoid foods with a barcode. Stick to the produce aisles and buy meat, fruits, vegetables, and nuts. Opinions and preferences vary on dairy, but I like it, so I throw that in as well. Foods to avoid are most things that come in boxes, cans, jars, etc. Not because of some vague "Chemicals/preservatives" argument, but because of a specific additive know as High Fructose Corn Syrup (HFC). The stuff is a nutritional disaster, I'll spare you the details of why, but it's to be avoided.
Things that all but guarantee weight loss are cutting back on or eliminating booze and soft drink. Booze has the effect of basically stalling the body for a day, and soft drinks are pure HFC. Both will greatly hinder weight loss. Diet soft drinks aren't good by any means, but switching to diet is better that sticking with full sugar.
Once you have your foods in order, calculate your BMR and TDEE. There are calculators for this online. I recommend also putting some time into reading up of macronutrient and micronutrient requirements too. Eating a balanced diet is likely to hit all the requirements anyway, but being deficient in one is a good way to be hit with crushing cravings. Make up some meal plans that put you in the right range of what you need, and that's pretty much it. The first few weeks require a bit of active thought, effort, and willpower, but once your eyes learn what a healthy day's food looks like, and once your body gets used to a quality intake, it becomes thoughtless and weight loss happen automatically.
