SHOP as in WooCommerce main shop page can be changed to anything you want: wp admin > woocommerce > settings > products > display: Shop Page
Just change that page to whatever name or url you wish.
Then save your permalinks.
You can also alter the permalinks, yes.
The main thing this will affect is if you have any built-in links throughout your marketplace (they’ll also have to be updated) or if your site has been indexed by google, the links will be dead unless you use Yoast or another plugin to update/redirect links.