sorry but that is not right about juice= 1 orange.
To get the same amount of juice in 1 glass you'd need to eat around 4-5 oranges. No one does this normally in one meal and it raises blood sugar just like any other sugar. If you eat the actual fruit you are also digesting some fibre too.
This was in the news last week but it's been discussed now for about a year.
Main meals should be more protein and more veg and fewer carbs. eg 40% protein, 40% veg, 20% carbs.
A portion is a large handful.
I don't think you can count fruity cereal as a portion of fruit- there won't be enough and if it's mainly raisins or other dried fruit that is very high in sugar.
On an average day I might have 2 pieces of fruit , plus salad for lunch including peppers, celery, watercress, lettuce, maybe a small avocado 3 x a week, or homemade veggie soup for lunch, mushroom omelette, then for my main meal I might have 3 from: carrots, green beans, cabbage, broccoli, peas, roast veg ( aubergine, peppers, butternut squash, sweet potatoes) , spinach, mushrooms, courgettes, .....
Does this help?