Hi, Mystie, and welcome to bonsaiTALK!
Sorry to be the bearer of bad news, but it sounds like your juniper is dead
By the time it turns brown and brittle as you describe, it is usually too late. Junipers have a disconcerting habit of staying green even after they are dead, so unless the green bits are still flexible and soft, it's beyond hope. ...
The good news is that you've been introduced to a wonderful new hobby, and anyone here can tell you that dead trees are the tuition we pay for learning bonsai. I suggest you get a ficus and keep learning
sorry
pootsie