Curious
A little expertise and knowledge is needed - my DP knows how to fell trees safely, and how to use the equipment required such as chain saws etc. He could already do this before we bought the woodland, as we have a large garden, and an allotment. Also woodwork has been one of his hobbies for many years.
You will need to be able to recognize and remove any dead or diseased trees, as well as the permitted volume of timber each year if you want to. (There are rules about how much healthy wood you can remove). You may also have to maintain pathways or fences/walls etc. We have a dry stone wall along one edge of our woodland, although the farmer next door looks after that.
As for costs - apart from equipment, which for us is mainly chainsaws and safety clothing, axes, saws, wedges etc, plus a trailer to transport the wood, there hasn't been much more.
We have cleared an area for camping and picnics, have installed a storage shed and this spring we are going to build a pizza oven! (Very excited about this!)
There are rules about what you can put on the woodland - mainly it's about not being allowed to live there - but things like storage sheds or a shipping container etc are allowed.
So there is some knowledge required. Of course it is possible to pay someone else to do it, or part of it, but my DP loves to do it all himself. We sometimes need help but friends and family are happy to pitch in in exchange for camping rights! I believe that there are courses you can go on to learn these skills if needed.
Please let me know if you have any more questions. I say go for it, it's such a pleasure to have such a beautiful place to go!