How to customize Apple Watch faces?

Where is the official software for creating watch faces, or am I stuck having to pay a subscription for this? I've checked a few different ones, and most of them seem to have a monthly sub of 5$ a month, which I find insane for something like a watch face.

Also, I'm seeing that every digital watch face has the clock on the top. Is it possible to center this? If not, I'll have to bring the watch back, as my OCD will never allow something like that!! I'm sure this can be done, as there is no reason to not allow the digital time display to be moved wherever you should want it.

[Re-Titled by Moderator]