Battery, USB-C ports and MagSafe connector have distinct guides for the base M3 model.
What to check before buying
Charging
iFixit covers USB-C port replacement and a separate MagSafe port procedure. A damaged connector can be considered without assuming a screen or mainboard replacement.
Other repairs
Battery, fan, screen and trackpad also have guides. The base M3 and M3 Pro/Max 14-inch versions should be identified before ordering parts.