Hi, I am Van. I'll be glad to assist you today.
Yes, you will be able to add and change your display language. However, adding a new language will not completely change the language on the system. Some parts will still display the language that the system originally had.
If you need to set the whole system language, I recommend that you clean install Windows 11 Home and select your preferred language during the installation setup.
Note: Make sure to back up your important files from your main Windows drive to another drive or external hard drive before you reinstall the operating system. Because reinstalling Windows will delete everything on the main Windows drive.
Please let me know if you need any further assistance. I will be glad to assist.