Congratulations on getting your land.
If you are unable to visit daily, and don't have someone who would do daily checks for you, you can't have any livestock.
You will need to check the current designation of the land. If it's classed as agricultural you may need to apply for planning permission for change of use in order to grow vegetables or to plant trees. (Unless of course you grow an acre of turnips - then it's an agricultural crop!
But trees need change of use on agricultural land, whether they are a crop like willow or not, and ploughing needs permission on some land.) Ask the council what it is classed as now and how to go about getting a change of use if you need one.
If the sward is a mess and the soil poor it would be a good idea to have pigs clear it and fertilise it before you try to grow any veg. But if you can't do daily checks then maybe planting an orchard would be a better bet. It would look lovely, give you lovely fruit, and would mean you could have livestock at a later date if/when you are in a position to look after them properly. You would need to put feed in the planting holes for the trees and feed the trees annually of course.
You can get soil test kits from gardening shops. The likelihood is it will be poor if it has had ponies on it. Some people grow potatoes as a 'clearing crop' then the soil is easier to work the following year. (Potatoes will grow with no fertiliser, you just get a lesser crop. But you do have to cover the tubers somehow to keep the light off them.) I am sure others will be along with more and better ideas shortly!