Is this a good idea for a book or not?

Ok so to everyone who read my old one sorry about the grammar and run on sentence im fixing this now here it is. Ok so my books about a kid who lives in the middle-age times. He as always loves sword fighting and has practiced it since he could remember. His father gets him a real sword and shield when hes 14 so he doesn't have to use his old wooden ones. Then the army comes recruiting looking for a new recruit. So he joins (his father wasn't to sure at first) but he ends up joining. His new master learns of a a plot to open a portal to let in these orcs. Their master is looking for revenge (not giving it away) so he has to bring a VERY important item to close the portal. On his journey to the portal he meets 2 new friends one archer and 1 swords women. When he gets there he has to get to the portal and throw the item in it to destroy it. The orcs are already coming out and he has to help he army hold them off and he has to get in. But when he gets there he learns a BIG secret. Their master is holding something that determines the fate of their world. (The enemy master doesn't know he has it). So if he destroys the portal their world dies. So he has to go in there kill the master and make it out with the item, but he only has 2 hours or else the orcs will overrun the army and scatter everywhere wiping them all out. Im still in the process of writing please bear with me. Also I need ideas/comments. Would you read it?