Welcome to the forum NovicePaul.
In answer to your question, a pair of walking boots, which will give the necessary ankle support. If you intend to use them only in good conditions, then a lightweight pair will be fine, as long as they fit well. No need to spend a lot of money.
If you intend going out in wetter conditions, then I would recommend a leather pair rather than fabric, which in my experience always disappoint when the going gets tough.
What sort of experience of hillwalking do you have?