I'm not sure if there is a good breed for a beginner, everyone would recommend their own favourite breed, mine are pure Toggenburg, I believe they were originally bred for cheese making, they are placid (but mischievous at times

), if you want to help a rare breed this could be the one to go for.
Anglo Nubian are known for high butterfats, but they have a reputation for being noisy.
Much depends on upbringing, temperment, and possibly age?
I too would suggest a milker and daughter(s), (making sure she is already being milked and calm about it), but not too old.
Don't forget they need shelter if turned out, and they will strip and kill any trees they can reach

.
They will of course help keep the weeds down, and help clear a wild area, manure is good if composted, they do tend to waste hay and grass seed will be in fresh manure.
Milk can be used for orphan lambs, not sure if the whey can still be fed to pigs or chickens (defra rules and regulations

)
Check out BGS and RSPCA websites for advice on care.
BUT BE VERY CAREFUL you may intend to only keep 2, but find yourself falling in love with the babies and end up wondering where to keep them all

(experience talking

)