For dietician advice https://challenge22.com/nutrition/
You can also sign up to veganuary and get lots of tips and recipes.
Food wise, yes the best way to eat is whole foods plant based.
The following are good to include-
Various beans (kidney, haricot, butter, black eye, chick peas etc). Can eat these as pate, hummus, in chilli, in curry, in soup, in salad etc.
Lentils- the green ones go well in pasta or shepherd’s pie etc as a mince replacement and the red ones make good soup.
Nuts- peanuts, cashews, Brazil nuts, hazelnuts, pecans, pistachios etc- as a snack, in porridge or cereal, as a nut butter on toast, ground in baking and so on.
Seeds- chia, flax, pumpkin, sunflower etc in bread, ground flaxseed can go anywhere, cereals, soups, baking, can make chia pudding, both chia and flax mixed with water make an egg substitute.
Veg- especially green leafy types, but all veg and as much as possible- should be half of the plate at each dinner. Can get quite a lot of veg grown in UK.
Fruit- especially berries when in season, but all fruit.
Wholegrains- pasta, bread, couscous, rice, quinoa, oats etc.
Oils, spices, condiments, herbs and so on.
It doesn’t need to be expensive or hard. Pasta with a tomato based sauce and green lentils. Oat porridge with chopped fruit and nuts. Baked beans on toast. Etc.