First you need to rule out dirty and/or improperly seated connectors: disconnect the 2 screen cables from the logic board (step 17 from this guide, marked in orange and red).
Clean the touch connector on the board and on the screen cable (gently, the one marked red) using a cotton swab dipped in 90%+ isopropyl (rubbing) alcohol.
Reconnect and test your phone.
If issue remains, put back the old screen. If touch function is restored, either your new screen was defective to begin with, or it was good but you damaged the cable by creasing or tearing during installation. It happens sometimes that when you pull the 2 cables through the frame, they get stuck and torn, OR you don't pull them far enough, and they get compressed between the frame and LCD and get creased/damaged.
If using the old screen does not restore touch function, you may have damaged something on the board. Start by disconnecting all the connectors in step 17, and examine the logic board around those connectors, looking for something missing/broken/part removed. Let us know what you see, if you see something like that.