BlackCat are you trying to do a budget meal plan or just a meal plan?
If I am just doing a meal plan I choose the recipes that I fancy and then write down the ingredients I haven't got on the shopping list.
If I am doing a budget shopping list and looking for meal ideas I sometimes go to the BBC good food website and enter in the ingredients that I have and see if any of the ideas it comes up with appeal.
On the fresh veg front I try to buy all of it for a week. I will put the meal using the brocolli early in the shopping week and things using peppers or courgettes later in the week as they keep quite well.
The other option is to cook large portions and once it is cooked it should keep a few days to be used later in the week
I find if I am doing a lot of new recipes my shopping costs go up as you sometimes need a tube or jar of something new that you haven't got in the store cupboard (eg marmite or mustard or redcurrant jelly) but that cost vanishes if you like the recipe and use it again and again as you can dip into the jar again and again.
What recipes are you thinking of trying?