Hello Paula,
You will have a healthy diet if vegetables are the base of your diet. It is also very important to include daily fruits, nuts, seeds, dairy products and whole-grains. Complete your diet including every week lean meat, eggs and legumes.
Avoid as much as possible sugary products, processed meats, ready meals and junk food.
If you don't eat fish, you will get good quality proteins from lean meat, eggs, dairy products and legumes. In this case it is especially important to eat enough nuts, which will provide you with the good fats that the fatty fish contain.
If you don't eat any seafood at all, I recommend you to use salt rich in iodine for cooking.