I like Beagles, I only know 5 but they all have lovely temperaments, lovely friendly dogs, 2 can not be let off lead at all the owner has no control over them whatsoever, they are off, off and away! Partners in crime. 3 others I know are let off lead, but only when around doggie friends whom they have known since they were pups, as they will stay with them and the dogs all go exploring together, guess it is a pack thing.

and just need leading when directions are changed or at home time.
Usually when you have a dog already a pup will bond with it and they will walk explore together, not sure if this is the same with Beagles though, it may well have a mind of it's own.
As already said, safe area's will be the key and plenty of training, though instincts often can over-ride them. But for temperament and dog friendliness IME they are really nice dogs.
(Well.......... unless you are a fox

)