The drain bolt is likely the same as on 6th gens, which is on the left side about 17 cm or so forward of the shift lever pivot. A hand mirror slid underneath should make quick work of locating it. No need to remove plastics on 6th gens for access, I would guess similar on your '14.
No need to remove the bellypan to access the drain plug, but you need to remove the rhs of the bellypan to access the filter, (unless you have the evap canister) and you reach across from the right to the filter on the LHS. In Australia we have the euro version and it has no evap canister here, yours may be different??
The filter will hold its volume of oil, preventing a complete oil change unless you drain it.