So I’m making my story. I need a site or something to help me plan out the events, instead of making it up as I go. So if anyone can recommend me the sites and how they work, I’d be very grateful! 
I just use one big ol’ pages document.
Keep a list of scenes and plot events that you want to include. Write a chapter overview, e.g.:
Chapter 1 - Rising Tides
You and love interest visit a cave system. X happens, you find X, love interest confesses X.
Cliffhanger: You are trapped in the cave as the water begins to rise.
Chapter 2 - Dumb Luck
You wake up outside the cave, with love interest looking down at you after performing CPR. They can’t explain how you two escaped, but they have a gash down their arm. They insist on taking you to the hospital.
Cliffhanger: You insist that love interest receive medical treatment too, but they are completely healed.
There’s also a site called notebook ai (https://www.notebook.ai) which lets you keep track of characters, locations etc. but doesn’t really cover events.