Windows 11 has a few interesting features and a nice new rounded corner aesthetic, but what's the Start button doing in the middle of the screen? The change from a left-aligned taskbar to a center-aligned taskbar is hard to get used to, but it's pretty easy to overwrite Microsoft's design choice and move the Start button and taskbar icons back to the left.
To move the taskbar left, right-click anywhere on the taskbar and select Taskbar Settings from the pop-up menu—if you can call a menu with one item in it a menu. This will take you directly to the Personalization > Taskbar screen.
Here you can add/remove some of the items that appear on the taskbar, such as Search, Task view, Widgets, and Chat, which can be useful for keeping it clean.
The option you're looking for can be found at the bottom of this screen: Taskbar behaviors. Expand this section by clicking on it, and then set the taskbar alignment to 'Left' and you're done. Windows the way you know and love.
Of course, it's easy to return it to a more central position from this screen. Just set the taskbar alignment back to 'Center.' This is also where you can elect to automatically hide the taskbar, as well as setting whether it appears on all of your displays.
If you're curious as to why a certain icon isn't showing up in the tray anymore, here's a list of Windows features that were dropped from Windows 11. So long, Cortana! (She's still around, just a little more hidden.)