They are related, but they are not the same kind of word.
So:
This sentence uses both because one refers to the craft, and the other refers to the person associated with the wheel.
Because tour is one of those French words whose meaning changes with gender.
In le tour de potier, it is the masculine noun tour, meaning the wheel-like device used by a potter.
So la tour de potier would be wrong here.
It is grammatically correct, but it does sound a little playful because of the repetition:
That repetition is not wrong at all. In fact, it can sound neat or memorable. But in more natural everyday writing, a French speaker might sometimes choose a different wording to avoid the echo, depending on style.
Still, as a sentence for learning, it is perfectly fine and very clear.
The comma separates the opening location phrase from the main clause:
The comma is natural here, especially in writing, because the sentence begins with a location phrase. French often uses this kind of structure.
You could also say:
That version is also correct, but the emphasis is a little different.
A rough pronunciation guide is:
dahn la-tu-lyay duh poht-ree, luh toor duh poh-tyay toorn
A few important points:
If you want to sound more natural, focus especially on the rhythm and on not pronouncing every final consonant the way English does.