Getting a new plot is so exciting, lucky you!
You've had some pretty excellent advice so far, as you always will on this forum. The only thing I would add is to think about what you want to grow and why you want to grow it before you just start sowing and planting.
Relatively easy crops to grow include peas, beans, onions, and of course potatoes, but these are also fairly cheap from the supermarkets, and don't taste that much different whether they're freshly picked from the plot, or bought from the shop (the exception is of course peas eaten raw, straight out of the pod, but if you're cooking them they taste hardly different to those frozen).
If the plan is to save money then perhaps it might be worth looking at what costs the most money from the supermarket. Things like mange tout, mini corn, French beans are all pretty pricey, but are relatively easy to grow.
If you want to focus on things that taste better fresh then carrots and tomatoes are (in my opinion) the most noticeable in terms of flavour from the plot than from the shops.
If you just want to grow stuff, and enjoy being outdoors, then just plant whatever takes your fancy. Some things will do great, others may fail miserably, but you'll hopefully have fun trying!
Good luck whatever you choose.