Just submitted my first order to Abu Games

or even foil snapcaster
i started around m14 debut but now im starting to get into non standard cards omg lol
but now im starting to play in standard so im torn between trading for older cards or standard cards

I see the issue.
Preordain is not legal in the Modern format.

ponder is banned in modern as well.

I'd suggest serum visions and sleight of hand as replacements.

In general mono black is a very good deck.  The caveat is it's only very good in the hands of a good player.  An inexperienced or bad player will notice the deck under performs markedly so.

Owen Turtenwald with channel fireball has been piloting the decks in the big tournaments I suggest you read his articles.

Some general play advice for the deck though.  It's a 1-1 grind.  You need to appropriately answer all your opponents threats with the 1-1 removal you have at your disposal. If you answer a threat with the wrong card, it could definitely come back to haunt you later. It's a constant check on what's on the board/hand to see if you can maintain the currently state and only using your removal when it's appropriate.  At some point during the game you will be able to turn a corner and take over the match by using underworld connections to bury them in card advantage or desecration demon/pack rat for board advantage. 

Also, don't be afraid to go all in on pack rat, it's a strong play in the format and mutavault synergies with it very well.  Against some decks though before you can take over with pack rat you'll get extremely low on life/resources so it can be unnerving at first, but you'll have to get a feel for when it's right to go all in.