It's often harder to understand and doesn't really make a good first impression, whether you're an experienced mapper or not.
As for your mod idea, have you ever heard of 'foxing'? Since you want to base your mod on Zelda, you'd better ask them permission to use their characters and such. It has happened several times before that mods were canceled by game studios...
Now onto modding... Such a thing would cost a pretty large amount of time to do it right. Not only would it involve model replacing but for proper behaviour also coding. The level-design is also something not to be taken lightly. So if you're really serious, you'd better start training yourself and get more experience in the area of level-design.
It's not an impossible task, but one that is often underestimated... so, know what you're aiming for...