Hey Hun, Welcome to the Forum
Its great that you are thinking ahead in planning for TTC, the best way of eating healthily I find, is to cut out the crap e.g crisps, dont buy them then you cant eat them lol.
Im a Major Crisps Fan, I dont have a sweet tooth, im a savoury kinda gal! Pasties, crisps, butties and so on..
Try buying in Jacket Potatoes they can be done pretty quick in microwave, and have a filling such as beans ad a bit of cheese or tuna with low fat mayo.
You can buy healthy ready meals but I find they dont fill me up enough.
Treat yourself once a week with something yummy that you really like.
You can buy some multivitamins from anywhere. supermarkets do their own brands so they arent expensive.
Plenty of fresh veg and fruit is great for you, but may put up the shopping bill, so try frozen veg that you can steam in the microwave or frozen fruit that you can blend into a smoothie
Good Luck x