Sheep are rewarding, great fun and very very sweet!!! I am so glad we got some. We are just 9 months in and loving it! I am probably not the best to advise you on the legal stuff. Still learning myself and don't want to get anything wrong, however from our steep learning curve, here is some advice for practical stuff:
Make sure you have sturdy, fairly high fencing - depending on what breed you get, they will try to escape from wherever you want to keep them...
Bucket train them. small amounts little and often with a repeatable call. once you can get them to follow you with a bucket into a stable/enclosure/new field/trailer, it will make your life soooo much easier
Have a small area/stable where you can herd them into and easily catch them for inspection/treatment/shearing - invaluable and so much better than chasing them around a field
Check for fly strike EVERY DAY during the fly strike weather. It is easy to treat if caught early but disgusting and disasterous if not noticed. Keep a stock of fly strike preventative and treatment remedies.
if you want to breed, don't do what we did and let the ram leisurely take his time over the ladies....it will give you a very long drawn out lambing time....
If you want to start lambing, be prepared for the worst - buy the whole kit of everything you will ever need and hopefully you won't need it. We were prepared for the very worst and had a thankfully uneventful lambing
Dont expect to make millions of pounds from sheep but do expect it to be fun challenging and a great experience. They are wonderful creatures - full of character and quirks. You'll love it!