Changed fuel pump now car will not start

If everything is hooked up and you are not getting any fuel then the new pump is faulty. I would double check the fuel pressure and make sure you can hear the pump coming on when you turn the key on. If you hear it and you have no pressure then the pump is most likely the issue. If you do not hear it then we need to check power at the pump and make sure you have 12 volts.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know if you have questions and we can go from there. Thanks

Did you use an OEM pump? I ask because the fuel pump control unit is a coded unit and it may need to be recoded to the replacement pump once the power to it was removed. The service information is a bit vague on if it needs to be if you replace the pump or not. Being a BMW it wouldn't surprise me that it did.

Service info shows you need a BMW scan tool, but I would think any of the better tools should do it. The info is very vague though, for example it shows removal and installation, but actually stops at the end of removal and just gives the torque for the fasteners.
If you would like to look at it https://www.newtis.info/tisv2/a/en/