After starting the car the brake pedal goes to the floor?

Hello,

Just to we can cover the basics. Have you already bleed the brakes?
Do you see any type of leak?

https://www.2carpros.com/articles/how-to-bleed-or-flush-a-car-brake-system
https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Also did you have an issue with pedal going to the floor before you did those replacements?

If this issue did not exists before then it could be one of the components that got replaced.

It could be something with the brake booster. Make sure the vacuum check valve is connected on the booster.

I just like to have a clearer picture of what you are experiencing this will help figure out the issue.

Let me know bit more info.
Thank you.