1
Open the Settings App.
Go to Personalization - Taskbar.
In there, in the Taskbar Alignment section, you can reset the Taskbar location to its default and also ensure the Alignment is set to Center and Taskbar size is set to Default.
2
Go to Personalization - Colors.
In the 'Choose your Mode' section set that drop-down menu to Light or dark depending on your preference.
3
Go to Personalization - Themes.
Set that to the Windows Default Themes.
4
These steps should reset the look and feel of Windows and the Taskbar.
If not, please provide a screenshot indicating the problem you are seeing.