As Ninthace has said.
If you are happy to follow a map you will find the paths in that area generally well waymarked and open to walk so devising your own route not too difficult. There are many books of walks available but often the directions in them are a bit vague so having a map (paper or phone) is often a huge help.
If you decide to buy a paper map
https://dash4it.co.uk are good for discounted Ordnance Survey maps. Buy the 1:25000 Explorer no.9 preferably waterproof (It rains down here! but if you buy a waterproof one it should guarantee dry weather for our trip!!))
Like many others on here, I use Viewranger on my phone. Again it's worth paying for the Ordnance Survey maps.
You have boots, so the only other clothes are waterproofs - Regatta is just as good as the more expensive brands - and a back pack. Again the cheaper brands are fine for day walks when pretty much all you need is the space for lunch/drink and your waterproofs if the sun shines. I love my Alpkit Gourdon waterproof day sack,
https://alpkit.comPS the sun does shine - occasionally -