The Vala Aulë, creator of the Dwarves, invented a language for them, and taught this language to the first Dwarves.
The Dwarvish runic alphabet is simple to use (much easier than the Elves' Tengwar).
The Dwarvish language (Khuzdul) is difficult to study – not least because we have very little information about it. Don't expect to be conversing fluently in Dwarvish. Tolkien simply didn't leave enough information about the language.