In the PrestaShop back office (Shipping > Carriers menu), you can set up several shipping methods.
See the official tutorials for setting them up here: Shipping & Logistics
All carriers are displayed on the storefront if:
- they are enabled for the zone linked to the customer's country
- the product(s) in the cart are not restricted to a specific carrier in the product page options
Note: the Stock per Store module follows this default behavior unless specific options are configured.