I agree with @Pampered chicken girl above - just get females and find someone with a buck you can breed them with, or get AI done by the vet. Read my post on this thread - it's full of reasons a billy or buck is a huge challenge to deal with. If you just want to add to the herd but not more...
I had a few dwarf or pygmy goats for a few years. One was a fainting goat and he was hilarious! But all of them were entertaining and the easiest creatures to care for on a daily basis.
Some of my thoughts:
I recommend NOT getting a billy, or if you do, get him castrated. In the presence of...