Congratulations on being the new owner of what sounds like a beautiful space.
If you are a first time gardener, I would be very careful about over-doing it. Turning your 5 acres into the kind of oasis you want it to be, will be a long term on going project for years. What you should be doing now is mainly a lot of careful thinking and planning. Think about what things you would like to be doing on your land and would like to have: will you have a boat on the lake? Woods with walking trails, orchard, fountain, fire pit, outdoor kitchen, eating space, hanging out with a book space, flower gardens, herb gardens, kids play space, lawn, equipment storage shed, vegetable garden, composting area, brush pile. Do you have ambition some day to have most of your produce come from the vegetable garden or you just want a few fresh tomatoes? You have land enough not to have to choose, you can pretty much do it all. Make a detailed large scale map of your land and start planning out what goes where and where paths will be. Then you can make it happen a little bit at a time.
Put your veggie garden near enough your house so it is easy to get to, run out and pick something for supper, but in a full sun area, where it is not shaded by trees. Personally I think it keeps it manageable and organized to lay it out in beds with paths between. Shovel the topsoil off the paths on to the beds and you have raised beds (they not need to be boxed in or anything and it would be a waste, with how much room you have). Four 8x4 beds will be
plenty to start with, unless you are retired and planning to work in the yard full time-- maybe even then. Getting the soil ready and prepped is the main thing you should be doing this time of year.
If you have some veggie beds ready soon, you could plant some cool weather stuff like beets, broccoli, cabbage, and in October plant garlic cloves.
Here's a planting guide, what to plant when, for zone 5-6. If that doesn't include you, you can reset it to your zone.
https://www.thevegetablegarden.info/reso ... g-schedule
Remember take it easy and keep it fun!

If you have success with a few veggie beds, that is way better than starting a huge plot and then it gets all weedy and full of bugs and you get all frustrated and hate the whole thing....