I am very new to D&D 5e. The whole idea behind the character is that they can manipulate metal decently almost telekeneticaly, like throw a knife and control it in the air or tangle the bad guy up with some chains. Only issue is that I can't figure out how the magic system works nor can I figure out how to do this with a charcter. Is there something specific like an item to make this work or should I scrap the idea?
It sounds like you're new to 5e and you're trying to do character creation.
The approach you've taken is you've decided on a character concept -- you want to build a character that can control metal -- and you want to build that as a 5e character.
My advice is that, as a first-time player, you'll probably have more fun if you choose one of the existing character classes and follow the standard rules for character creation. Once you understand how the system is supposed to work, you can then experiment with new character concepts.
The best path to building a "character that can control metal" concept will probably be re-flavoring an existing class. For example you might take the warlock character class, which normally deals damage using eldritch blast:
A beam of crackling energy streaks toward a creature within range. Make a ranged spell attack against the target. On a hit, the target takes 1d10 force damage.
and you'd re-flavor it as telekinetic metal blast:
A cloud of metal scraps streaks toward a creature within range, flung by your telekinetic metal-controlling powers. Make a ranged spell attack against the target. On a hit, the target takes 1d10 force damage.
When your warlock got other spells and powers, you could reflavor those too if you wanted.
This doesn't change any game mechanics -- it only changes the narrative -- so your DM is more likely to be willing to let you create a character that does this.