Blue yeti pro plugged in wit xlr wires into scarlette 2i4 and when i want to listen while i sing it is delayed ? Also what would be a good voice filter for rap vocals ?

You are having issues with latency. Make sure you're using ASIO drivers, and experiment with how low you can set the latency without causing computer glitches.

Where could i get asio drivers ?shouldnt it already come with sonar ?

They're usually provided by the audio interface manufacturer on a disk. If you have no disk, they can be downloaded from Focusrite's web site. 
Press P on the computer keyboard to bring up your Preferences. You can find out there what your current settings are and also make changes.

This is a USB mic, isn't it?  These were designed for podcasting, not music recording.  No doubt you got that because you don't have an audio interface to plug a "regular mic" into.
 
Sorry, I don't have any experience with a USB mic, so can't offer any specific suggestions. 
 
I'm sure there are folks here using USB mics, and will be able to help you.  Good luck.

I checked and it is a USB mic, although the OP says he's using XLR wires to connect it...

Okay, I just googled your mic and it's an odd duck: a combo digital (USB) and analog (XLR) mic.
 
It sounds like you're trying to connect the XLR end which (to my mind) shouldn't require drivers.  Is there an analog/digital switch you may have overlooked?
 
Read the manual again, and make sure you are following the correct steps.

I will unplugg and redo everything but ive done this before with no results... Any possibility my computer isnt strong enough (prosseser, sound card ect.) ?

Besides the audio driver and buffer configuration, watch out for the latency caused by certain effects used in your project. (Search for Plugin Delay Compensation, or PDC).

Blank audio track or even without the program.... If i listen to the mic using xlr or usb it comes out with a delay im really new at this stuff thanks for any help n advice !