Questions about installing Microsoft Office 2019?

I have a new notebook (Windows 10 Professional) on which I want to install the package "Office 2019 Standard".
But I have a license key for two computers and can download the software (on the PC everything is on it).
Now I have seen that all Office programs are preinstalled on the notebook. If I open these individually, the input of a key is requested in each case.
Should I just type in my existing key into the programs that are included in the standard package?
Or should I ignore the preinstalled programs and rather download them via the download link and then unlock them with the key?
Which one is better or right?

If the programs already installed are the same ones you plan to install then you do not need to do this anymore. If you are z.b. Word opens then you can enter the key that should then transfer to all others, so on Powerpoint, excel etc…

Uninstall standard programs and download Office 2019.

I would also recommend a deletion of the existing progs and then a complete reinstallation.

This has various advantages like

Choice of storage location and also the storage data (I have, for example, neither the Progs nor Outlook PSTs on C: but on another partition (is handy when restarting))
Choice of 32 or 64 system

I did it that way and it worked.

With pleasure.

I can only recommend that with the PSTs if you have an SSD with Win10 on it. This saves you a lot of daily access to the SSD and extends their life a little ;-)