underwater effect 2D

Hello,
I never created a shader but I am currently working on my first "real" game where I want to add a "simple" rising water effect in Unity 2D. This should only be a visual thing. A moving water surface and some underwater distortions would be great. I read a lot online and they mentioned shaders very often. But I do not really understand how this works. Are shaders really the way to go? How do I add a shader?
Or is this something really big I should not bother about in my stage of unity skills?
Thank you.