How to Handle Redirects for my Login Page PHP

I have recently moved from localhost to my live website. I have a simple PHP login page. After the users details are checked with my mysql table and if the username exist and they provide a valid password for that username they are redirected to the home page. I was using the header function built in to PHP but this seems to be no longer working now that I am on my live website. After further research it seems that I cannot use header tags after the page loads. So I am not echo'ing out script tags to window.location redirect to my homepage. The problem with this is that when the new location is being redirected to it appears to look like an additional web pages is loading in before my actual webpage that I'm wanting to go to loads in (This is probably due to the fact that I have extra error handling code that is running after the fact). Does anyone else experience this when using this method? Is there a better way to handle this?

This is what I'm using currently just in case there is any confusion

echo '<script>window.location.href = "home.php";</script>';