UE 4.26.2 couple questions

i cant seem to figure out how to get water to function right 9/10 I have like 25 ft without post processing.
aswell as i cant find how to make a matinee i only get access to master sequence and level sequence.

I am also struggling getting a wave system set up correctly i can get the enemies to spawn from a location but i ant get them to spawn at all locations nor can i get them to chase me no matter where they are on the map compared to me.

im trying to make a really large map and that may be part of my issue.

are there any tips as to how i can get these things to function correctly on large landscapes