Best Way to Switch to a New Macbook but without having the Second Macbook

Hey guys, As the weird title suggests. I have a Macbook M3 Pro that needs to be returned and I will get a M4 Air. Since the M4 Air isn't out yet, I won't have access to it when I have to return the M3 Pro. So what's the best way for me to back up everything from the M3 Pro so that it sets up the M4 Air exactly as I have done with M3 Pro? The Apps, the wallpaper, widgets everything. Thanks for the help.