thru hull drain holes

waltaa

I have a 27 fiesta vee,  knocked off one of the thru hull drain plugs . do not know how to access the back of the holes to attach whatever needs to be attached . There are 5 holes on the starboard side one for a/c discharge / one for sink ??? one for the shower ??? one for thr forward  bilge pump ??and I do not know what the other one is for ???

there are three larger ones and 2 smaller ones   , I knocked off  one of the smaller ones  four of these holes are grouped together aft of the head , the other larger one is under the sink [ I assume that one is for the sink ] if I do not attach the hose where will that water go , and will it be a problem until I can get it fixed . The one I knocked off is the lower most aft plug

                                                        any help will be appreciated