Installed new bath faucet. No cold water comes out
First verify that you have water coming through the cold line.  Make sure the shutoff value is turned off at the wall, disconnect the line from the faucet and put in a bucket.  Open the value and you should get a lot of water coming out at full pressure.

If that works, there is something wrong with your faucet.  Either something is blocking it or it's defective.  I once had this happen to me with a faucet from a big-box store.  I took everything apart to try to figure out what was wrong with it until I finally found that one of the valves was lacking a small grove that was the channel the water was supposed to come through.  It took me forever to notice it was different than the working side.  I went back and someone that worked there grabbed the part out of another box for me.

If this is a single handle faucet make sure you have installed the cartridge properly.  If it is not oriented right or the handle doesn't connect properly, you could have an issue like this.