How can I level quickly in Skryim to the point that I can get a daedric sword? [duplicate]

Since you don't have access to the console on Xbox, the fastest way to level is simply to use skills. But you don't have to reach a minimum level to get a daedric sword, only to find a daedric sword as loot.

If you get your smithing skill high enough you can craft one using leather strips, a daedra heart and 2 ebony ingots.

One sure location for a daedra heart is Enthir at the College of Winterhold but is also common around alchemy stations in dungeons. You can also find several in the final part of the quest The Black Star, assuming you loot the dremora.

Ebony can be found in Gloombound Mine, but if you don't have access to orc strongholds you can also find enough for a daedric sword in Redbelly Mine near Riften.